Direct growth of polyaniline nanotubes on carbon cloth for flexible and high-performance supercapacitors

ABSTRACT

The present disclosure further provides an exemplary energy storage device fabricated from rectangular-tube polyaniline (PANI) that is chemically synthesized by a simple and convenient method. The rectangular-tube PANI, as an active material, is synthesized on a functionalized carbon cloth (FCC) as a substrate, and the obtained composite is immobilized on a stainless steel mesh as a current collector. The present disclosure additionally presents a facile technique for the direct synthesis of PANI nanotubes, with rectangular pores, on chemically activated CC.

CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.15/472,409, filed Mar. 29, 2017, which claims the benefit of U.S.Provisional Application No. 62/317,120, filed Apr. 1, 2016, whichapplications are incorporated herein by reference in their entireties.

BACKGROUND

The development of high-performance energy storage devices has gainedsignificant attention in a broad range of applications. While normalelectronic devices progress rapidly, according to Moore's law, batterieshave advanced only slightly, mainly due to the limitations of currentmaterials' energy densities and capacities. As such, batteries with areduced charge time and an increased charge density may have a profoundeffect on the design and use of portable electronics and renewableenergy devices.

SUMMARY

Provided herein are methods, devices, and systems for growing nanotubeson functionalized carbon cloth. The growing may include the manufacture(or synthesis) of functionalized carbon cloth, the manufacture (orsynthesis) of nanotubes and nanostructures, and/or the manufacture (orsynthesis) of an electrolyte. Some embodiments provide methods, devices,and systems for the manufacture (or synthesis) of functionalized carboncloth and/or for the manufacture (or synthesis) of nanotubes andnanostructures and/or for the manufacture (or synthesis) of electrolytesand/or for the manufacture (or synthesis) of supercapacitors.

A first aspect disclosed herein is a device comprising a functionalizedcarbon electrode comprising a carbon substrate and a conducting polymerdisposed on the carbon substrate.

In some embodiments, the functionalized carbon electrode comprises apolyaniline functionalized carbon electrode.

In some embodiments, the carbon substrate comprises carbon cloth, carbonfiber, amorphous carbon, glassy carbon, carbon nanofoam, carbon aerogelor any combination thereof.

In some embodiments, the conducting polymer is a semi-flexible rodpolymer. In some embodiments, the semi-flexible rod polymer comprisespolyaniline, poly(p-phenylene oxide), poly(p-phenylene sulfide),poly(3,4-ethylenedioxythiophene), polypyrrole, polythiophene,poly(3-alkythiophene), poly(3-methylthiophene), poly(3-hexylthiophene),or any combination thereof. In some embodiments, the conducting polymerhas a nanotube morphology, wherein the nanotube has a cross-sectionalshape comprising a rectangle, a square, a circle, or a polygon.

In some embodiments, the nanotube has a length of about 100 nanometersto about 10,000 nanometers. In some embodiments, the nanotube has alength of at least about 100 nanometers. In some embodiments, thenanotube has a length of at most about 10,000 nanometers. In someembodiments, the nanotube has a length of about 100 nanometers to about500 nanometers, about 100 nanometers to about 1,000 nanometers, about100 nanometers to about 2,000 nanometers, about 100 nanometers to about3,000 nanometers, about 100 nanometers to about 4,000 nanometers, about100 nanometers to about 5,000 nanometers, about 100 nanometers to about6,000 nanometers, about 100 nanometers to about 7,000 nanometers, about100 nanometers to about 8,000 nanometers, about 100 nanometers to about9,000 nanometers, about 100 nanometers to about 10,000 nanometers, about500 nanometers to about 1,000 nanometers, about 500 nanometers to about2,000 nanometers, about 500 nanometers to about 3,000 nanometers, about500 nanometers to about 4,000 nanometers, about 500 nanometers to about5,000 nanometers, about 500 nanometers to about 6,000 nanometers, about500 nanometers to about 7,000 nanometers, about 500 nanometers to about8,000 nanometers, about 500 nanometers to about 9,000 nanometers, about500 nanometers to about 10,000 nanometers, about 1,000 nanometers toabout 2,000 nanometers, about 1,000 nanometers to about 3,000nanometers, about 1,000 nanometers to about 4,000 nanometers, about1,000 nanometers to about 5,000 nanometers, about 1,000 nanometers toabout 6,000 nanometers, about 1,000 nanometers to about 7,000nanometers, about 1,000 nanometers to about 8,000 nanometers, about1,000 nanometers to about 9,000 nanometers, about 1,000 nanometers toabout 10,000 nanometers, about 2,000 nanometers to about 3,000nanometers, about 2,000 nanometers to about 4,000 nanometers, about2,000 nanometers to about 5,000 nanometers, about 2,000 nanometers toabout 6,000 nanometers, about 2,000 nanometers to about 7,000nanometers, about 2,000 nanometers to about 8,000 nanometers, about2,000 nanometers to about 9,000 nanometers, about 2,000 nanometers toabout 10,000 nanometers, about 3,000 nanometers to about 4,000nanometers, about 3,000 nanometers to about 5,000 nanometers, about3,000 nanometers to about 6,000 nanometers, about 3,000 nanometers toabout 7,000 nanometers, about 3,000 nanometers to about 8,000nanometers, about 3,000 nanometers to about 9,000 nanometers, about3,000 nanometers to about 10,000 nanometers, about 4,000 nanometers toabout 5,000 nanometers, about 4,000 nanometers to about 6,000nanometers, about 4,000 nanometers to about 7,000 nanometers, about4,000 nanometers to about 8,000 nanometers, about 4,000 nanometers toabout 9,000 nanometers, about 4,000 nanometers to about 10,000nanometers, about 5,000 nanometers to about 6,000 nanometers, about5,000 nanometers to about 7,000 nanometers, about 5,000 nanometers toabout 8,000 nanometers, about 5,000 nanometers to about 9,000nanometers, about 5,000 nanometers to about 10,000 nanometers, about6,000 nanometers to about 7,000 nanometers, about 6,000 nanometers toabout 8,000 nanometers, about 6,000 nanometers to about 9,000nanometers, about 6,000 nanometers to about 10,000 nanometers, about7,000 nanometers to about 8,000 nanometers, about 7,000 nanometers toabout 9,000 nanometers, about 7,000 nanometers to about 10,000nanometers, about 8,000 nanometers to about 9,000 nanometers, about8,000 nanometers to about 10,000 In some embodiments, the nanotube hasan outer width of about 10 nanometers to about 1,000 nanometers. In someembodiments, the nanotube has an outer width of at least about 10nanometers. In some embodiments, the nanotube has an outer width of atmost about 1,000 nanometers. In some embodiments, the nanotube has anouter width of about 10 nanometers to about 50 nanometers, about 10nanometers to about 100 nanometers, about 10 nanometers to about 200nanometers, about 10 nanometers to about 300 nanometers, about 10nanometers to about 400 nanometers, about 10 nanometers to about 500nanometers, about 10 nanometers to about 600 nanometers, about 10nanometers to about 700 nanometers, about 10 nanometers to about 800nanometers, about 10 nanometers to about 900 nanometers, about 10nanometers to about 1,000 nanometers, about 50 nanometers to about 100nanometers, about 50 nanometers to about 200 nanometers, about 50nanometers to about 300 nanometers, about 50 nanometers to about 400nanometers, about 50 nanometers to about 500 nanometers, about 50nanometers to about 600 nanometers, about 50 nanometers to about 700nanometers, about 50 nanometers to about 800 nanometers, about 50nanometers to about 900 nanometers, about 50 nanometers to about 1,000nanometers, about 100 nanometers to about 200 nanometers, about 100nanometers to about 300 nanometers, about 100 nanometers to about 400nanometers, about 100 nanometers to about 500 nanometers, about 100nanometers to about 600 nanometers, about 100 nanometers to about 700nanometers, about 100 nanometers to about 800 nanometers, about 100nanometers to about 900 nanometers, about 100 nanometers to about 1,000nanometers, about 200 nanometers to about 300 nanometers, about 200nanometers to about 400 nanometers, about 200 nanometers to about 500nanometers, about 200 nanometers to about 600 nanometers, about 200nanometers to about 700 nanometers, about 200 nanometers to about 800nanometers, about 200 nanometers to about 900 nanometers, about 200nanometers to about 1,000 nanometers, about 300 nanometers to about 400nanometers, about 300 nanometers to about 500 nanometers, about 300nanometers to about 600 nanometers, about 300 nanometers to about 700nanometers, about 300 nanometers to about 800 nanometers, about 300nanometers to about 900 nanometers, about 300 nanometers to about 1,000nanometers, about 400 nanometers to about 500 nanometers, about 400nanometers to about 600 nanometers, about 400 nanometers to about 700nanometers, about 400 nanometers to about 800 nanometers, about 400nanometers to about 900 nanometers, about 400 nanometers to about 1,000nanometers, about 500 nanometers to about 600 nanometers, about 500nanometers to about 700 nanometers, about 500 nanometers to about 800nanometers, about 500 nanometers to about 900 nanometers, about 500nanometers to about 1,000 nanometers, about 600 nanometers to about 700nanometers, about 600 nanometers to about 800 nanometers, about 600nanometers to about 900 nanometers, about 600 nanometers to about 1,000nanometers, about 700 nanometers to about 800 nanometers, about 700nanometers to about 900 nanometers, about 700 nanometers to about 1,000nanometers, about 800 nanometers to about 900 nanometers, about 800nanometers to about 1,000 nanometers, or about 900 nanometers to about1,000 nanometers.

In some embodiments, the nanotube has an inner width of about 50nanometers to about 800 nanometers. In some embodiments, the nanotubehas an inner width of at least about 50 nanometers. In some embodiments,the nanotube has an inner width of at most about 800 nanometers. In someembodiments, the nanotube has an inner width of about 50 nanometers toabout 100 nanometers, about 50 nanometers to about 300 nanometers, about50 nanometers to about 400 nanometers, about 50 nanometers to about 500nanometers, about 50 nanometers to about 600 nanometers, about 50nanometers to about 700 nanometers, about 50 nanometers to about 800nanometers, about 100 nanometers to about 300 nanometers, about 100nanometers to about 400 nanometers, about 100 nanometers to about 500nanometers, about 100 nanometers to about 600 nanometers, about 100nanometers to about 700 nanometers, about 100 nanometers to about 800nanometers, about 300 nanometers to about 400 nanometers, about 300nanometers to about 500 nanometers, about 300 nanometers to about 600nanometers, about 300 nanometers to about 700 nanometers, about 300nanometers to about 800 nanometers, about 400 nanometers to about 500nanometers, about 400 nanometers to about 600 nanometers, about 400nanometers to about 700 nanometers, about 400 nanometers to about 800nanometers, about 500 nanometers to about 600 nanometers, about 500nanometers to about 700 nanometers, about 500 nanometers to about 800nanometers, about 600 nanometers to about 700 nanometers, about 600nanometers to about 800 nanometers, or about 700 nanometers to about 800nanometers.

In some embodiments, the surface of the nanotube includes one or morenanostructures. In some embodiments, the one or more nanostructurecomprise(s) a nanorod, nanochain, nanofiber, nanoflake, nanoflower,nanoparticle, nanoplatelet, nanoribbon, nanoring, nanosheet, or acombination thereof.

In some embodiments, the nanostructure has a length of about 4nanometers to about 400 nanometers. In some embodiments, thenanostructure has a length of at least about 4 nanometers. In someembodiments, the nanostructure has a length of at most about 400nanometers. In some embodiments, the nanostructure has a length of about4 nanometers to about 10 nanometers, about 4 nanometers to about 25nanometers, about 4 nanometers to about 50 nanometers, about 4nanometers to about 75 nanometers, about 4 nanometers to about 100nanometers, about 4 nanometers to about 200 nanometers, about 4nanometers to about 300 nanometers, about 4 nanometers to about 400nanometers, about 10 nanometers to about 25 nanometers, about 10nanometers to about 50 nanometers, about 10 nanometers to about 75nanometers, about 10 nanometers to about 100 nanometers, about 10nanometers to about 200 nanometers, about 10 nanometers to about 300nanometers, about 10 nanometers to about 400 nanometers, about 25nanometers to about 50 nanometers, about 25 nanometers to about 75nanometers, about 25 nanometers to about 100 nanometers, about 25nanometers to about 200 nanometers, about 25 nanometers to about 300nanometers, about 25 nanometers to about 400 nanometers, about 50nanometers to about 75 nanometers, about 50 nanometers to about 100nanometers, about 50 nanometers to about 200 nanometers, about 50nanometers to about 300 nanometers, about 50 nanometers to about 400nanometers, about 75 nanometers to about 100 nanometers, about 75nanometers to about 200 nanometers, about 75 nanometers to about 300nanometers, about 75 nanometers to about 400 nanometers, about 100nanometers to about 200 nanometers, about 100 nanometers to about 300nanometers, about 100 nanometers to about 400 nanometers, about 200nanometers to about 300 nanometers, about 200 nanometers to about 400nanometers, or about 300 nanometers to about 400 nanometers.

In some embodiments, the nanostructure has a width of about 4 nanometersto about 400 nanometers. In some embodiments, the nanostructure has awidth of at least about 4 nanometers. In some embodiments, thenanostructure has a width of at most about 400 nanometers. In someembodiments, the nanostructure has a width of about 4 nanometers toabout 10 nanometers, about 4 nanometers to about 25 nanometers, about 4nanometers to about 50 nanometers, about 4 nanometers to about 75nanometers, about 4 nanometers to about 100 nanometers, about 4nanometers to about 200 nanometers, about 4 nanometers to about 300nanometers, about 4 nanometers to about 400 nanometers, about 10nanometers to about 25 nanometers, about 10 nanometers to about 50nanometers, about 10 nanometers to about 75 nanometers, about 10nanometers to about 100 nanometers, about 10 nanometers to about 200nanometers, about 10 nanometers to about 300 nanometers, about 10nanometers to about 400 nanometers, about 25 nanometers to about 50nanometers, about 25 nanometers to about 75 nanometers, about 25nanometers to about 100 nanometers, about 25 nanometers to about 200nanometers, about 25 nanometers to about 300 nanometers, about 25nanometers to about 400 nanometers, about 50 nanometers to about 75nanometers, about 50 nanometers to about 100 nanometers, about 50nanometers to about 200 nanometers, about 50 nanometers to about 300nanometers, about 50 nanometers to about 400 nanometers, about 75nanometers to about 100 nanometers, about 75 nanometers to about 200nanometers, about 75 nanometers to about 300 nanometers, about 75nanometers to about 400 nanometers, about 100 nanometers to about 200nanometers, about 100 nanometers to about 300 nanometers, about 100nanometers to about 400 nanometers, about 200 nanometers to about 300nanometers, about 200 nanometers to about 400 nanometers, or about 300nanometers to about 400 nanometers.

In some embodiments, the electrode has an areal capacitance of about 150millifarads per square centimeters (mF/cm²) to about 750 mF/cm². In someembodiments, the electrode has an areal capacitance of at least about150 mF/cm². In some embodiments, the electrode has an areal capacitanceof at least about 750 mF/cm². In some embodiments, the electrode has anareal capacitance of about 150 mF/cm² to about 250 mF/cm², about 150mF/cm² to about 350 mF/cm², about 150 mF/cm² to about 450 mF/cm², about150 mF/cm² to about 550 mF/cm², about 150 mF/cm² to about 650 mF/cm²,about 150 mF/cm² to about 750 mF/cm², about 250 mF/cm² to about 350mF/cm², about 250 mF/cm² to about 450 mF/cm², about 250 mF/cm² to about550 mF/cm², about 250 mF/cm² to about 650 mF/cm², about 250 mF/cm² toabout 750 mF/cm², about 350 mF/cm² to about 450 mF/cm², about 350 mF/cm²to about 550 mF/cm², about 350 mF/cm² to about 650 mF/cm², about 350mF/cm² to about 750 mF/cm², about 450 mF/cm² to about 550 mF/cm², about450 mF/cm² to about 650 mF/cm², about 450 mF/cm² to about 750 mF/cm²,about 550 mF/cm² to about 650 mF/cm², about 550 mF/cm² to about 750mF/cm², or about 650 mF/cm² to about 750 mF/cm².

In some embodiments, the resistance of the electrode decreases after1,000 folding cycles by about 1% to about 8%. In some embodiments, theresistance of the electrode decreases after 1,000 folding cycles by atmost about 8%. In some embodiments the resistance of the electrodedecreases after 1,000 folding cycles by about 1% to about 2%, about 1%to about 3%, about 1% to about 4%, about 1% to about 5%, about 1% toabout 6%, about 1% to about 7%, about 1% to about 8%, about 2% to about3%, about 2% to about 4%, about 2% to about 5%, about 2% to about 6%,about 2% to about 7%, about 2% to about 8%, about 3% to about 4%, about3% to about 5%, about 3% to about 6%, about 3% to about 7%, about 3% toabout 8%, about 4% to about 5%, about 4% to about 6%, about 4% to about7%, about 4% to about 8%, about 5% to about 6%, about 5% to about 7%,about 5% to about 8%, about 6% to about 7%, about 6% to about 8%, orabout 7% to about 8%.

A second aspect disclosed herein is a supercapacitor comprising two ormore electrodes, wherein each electrode comprises a functionalizedcarbon electrode, a current collector, and an electrolyte.

In some embodiments the functionalized carbon electrode comprises: acarbon substrate comprising carbon cloth, carbon fiber, amorphouscarbon, glassy carbon, carbon nanofoam, carbon aerogel, graphene foam orany combination thereof; and a conducting polymer disposed on the carbonsubstrate, wherein the conducting polymer comprises polyaniline,poly(p-phenylene oxide), poly(p-phenylene sulfide),poly(3,4-ethylenedioxythiophene), polypyrrole, polythiophene,poly(3-alkythiophene), poly(3-methylthiophene), poly(3-hexylthiophene),or any combination thereof.

In some embodiments, the functionalized carbon electrode is apolyaniline functionalized carbon electrode.

In some embodiments, the current collector is metallic. In someembodiments, the current collector is ferritic. In some embodiments, thecurrent collector comprises stainless steel, crucible steel, carbonsteel, spring steel, alloy steel, maraging steel, weathering steel, toolsteel, or any combination thereof.

In some embodiments, an electrolyte is disposed between the firstfunctionalized carbon electrode and the second functionalized carbonelectrode. In some embodiments, the electrolyte is a redox electrolyte.In some embodiments, the electrolyte comprises an acid. In someembodiments, the electrolyte comprises a solvent. In some embodiments,the electrolyte comprises an acid and a solvent. In some embodiments,the acid is a strong acid. In some embodiments, the strong acidcomprises perchloric acid, hydroiodic acid, hydrobromic acid,hydrochloric acid, sulfuric acid, p-toluenesulfonic acid,methanesulfonic acid, or any combination thereof.

In some embodiments, the solvent comprises tetrahydrofuran, ethylacetate, dimethylformamide, acetonitrile, acetone, dimethyl sulfoxide,nitromethane, propylene carbonate, ethanol, formic acid, n-butanol,methanol, acetic acid, water, or any combination thereof.

In some embodiments, the concentration of the acid is about 0.5 molar(M) to about 2 M. In some embodiments, the concentration of the acid isat least about 0.5 M. In some embodiments, the concentration of the acidis at most about 2 M. In some embodiments, the concentration of the acidis about 0.5 M to about 0.75 M, about 0.5 M to about 1 M, about 0.5 M toabout 1.25 M, about 0.5 M to about 1.5 M, about 0.5 M to about 1.75 M,about 0.5 M to about 2 M, about 0.75 M to about 1 M, about 0.75 M toabout 1.25 M, about 0.75 M to about 1.5 M, about 0.75 M to about 1.75 M,about 0.75 M to about 2 M, about 1 M to about 1.25 M, about 1 M to about1.5 M, about 1 M to about 1.75 M, about 1 M to about 2 M, about 1.25 Mto about 1.5 M, about 1.25 M to about 1.75 M, about 1.25 M to about 2 M,about 1.5 M to about 1.75 M, about 1.5 M to about 2 M, or about 1.75 Mto about 2 M.

In some embodiments, the electrolyte is aqueous.

In those embodiments, the supercapacitor has a working potential ofabout 0.3 volts (V) to about 1 V. In those embodiments, thesupercapacitor has a working potential of at least about 0.3 V. In thoseembodiments, the supercapacitor has a working potential of at most about1V. In those embodiments, the supercapacitor has a working potential ofabout 0.3 V to about 0.4 V, about 0.3 V to about 0.5 V, about 0.3 V toabout 0.6 V, about 0.3 V to about 0.7 V, about 0.3 V to about 0.8 V,about 0.3 V to about 0.9 V, about 0.3 V to about 1 V, about 0.4 V toabout 0.5 V, about 0.4 V to about 0.6 V, about 0.4 V to about 0.7 V,about 0.4 V to about 0.8 V, about 0.4 V to about 0.9 V, about 0.4 V toabout 1 V, about 0.5 V to about 0.6 V, about 0.5 V to about 0.7 V, about0.5 V to about 0.8 V, about 0.5 V to about 0.9 V, about 0.5 V to about 1V, about 0.6 V to about 0.7 V, about 0.6 V to about 0.8 V, about 0.6 Vto about 0.9 V, about 0.6 V to about 1 V, about 0.7 V to about 0.8 V,about 0.7 V to about 0.9 V, about 0.7 V to about 1 V, about 0.8 V toabout 0.9 V, about 0.8 V to about 1 V, or about 0.9 V to about 1 V.

In those embodiments, after about 1,000 cycles of charging, thegravimetric capacitance of the supercapacitor reduces by about 4% toabout 18%. In those embodiments, after about 1,000 cycles of charging,the gravimetric capacitance of the supercapacitor reduces by at mostabout 18%. In those embodiments, after about 1,000 cycles of charging,the gravimetric capacitance of the supercapacitor reduces by about 4% toabout 8%, about 4% to about 10%, about 4% to about 12%, about 4% toabout 14%, about 4% to about 16%, about 4% to about 18%, about 8% toabout 10%, about 8% to about 12%, about 8% to about 14%, about 8% toabout 16%, about 8% to about 18%, about 10% to about 12%, about 10% toabout 14%, about 10% to about 16%, about 10% to about 18%, about 12% toabout 14%, about 12% to about 16%, about 12% to about 18%, about 14% toabout 16%, about 14% to about 18%, or about 16% to about 18%.

In those embodiments, after about 5,000 cycles of charging, thegravimetric capacitance of the supercapacitor reduces by about 6% toabout 26%. In those embodiments, after about 5,000 cycles of charging,the gravimetric capacitance of the supercapacitor reduces by at leastabout 6%. In those embodiments, after about 5,000 cycles of charging,the gravimetric capacitance of the supercapacitor reduces by at mostabout 26%. In those embodiments, after about 5,000 cycles of charging,the gravimetric capacitance of the supercapacitor reduces by about 6% toabout 10%, about 6% to about 14%, about 6% to about 18%, about 6% toabout 22%, about 6% to about 26%, about 10% to about 14%, about 10% toabout 18%, about 10% to about 22%, about 10% to about 26%, about 14% toabout 18%, about 14% to about 22%, about 14% to about 26%, about 18% toabout 22%, about 18% to about 26%, or about 22% to about 26%.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 1 amps/grams (A/g), of about 300farads/grams (F/g) to about 1,400 F/g. In those embodiments, thesupercapacitor has a gravimetric capacitance, in a current density ofabout 1 A/g, of at least about 300 F/g. In those embodiments, thesupercapacitor has a gravimetric capacitance, in a current density ofabout 1 A/g, of at most about 1,400 F/g. In those embodiments, thesupercapacitor has a gravimetric capacitance, in a current density ofabout 1 A/g, of about 300 F/g to about 500 F/g, about 300 F/g to about700 F/g, about 300 F/g to about 900 F/g, about 300 F/g to about 1,100F/g, about 300 F/g to about 1,400 F/g, about 500 F/g to about 700 F/g,about 500 F/g to about 900 F/g, about 500 F/g to about 1,100 F/g, about500 F/g to about 1,400 F/g, about 700 F/g to about 900 F/g, about 700F/g to about 1,100 F/g, about 700 F/g to about 1,400 F/g, about 900 F/gto about 1,100 F/g, about 900 F/g to about 1,400 F/g, or about 1,100 F/gto about 1,400 F/g.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of about 250 F/g to about 1,200F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of at least about 250F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of at most about 1,20F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of about 250 F/g toabout 500 F/g, about 250 F/g to about 750 F/g, about 250 F/g to about1,000 F/g, about 250 F/g to about 1,200 F/g, about 500 F/g to about 750F/g, about 500 F/g to about 1,000 F/g, about 500 F/g to about 1,200 F/g,about 750 F/g to about 1,000 F/g, about 750 F/g to about 1,200 F/g, orabout 1,000 F/g to about 1,200 F/g.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 10 A/g, of about 200 F/g to about 900 F/g.In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 10 A/g, of at least about 200 F/g. Inthose embodiments, the supercapacitor has a gravimetric capacitance, ina current density of about 10 A/g, of at most about 900 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 10 A/g, of about 200 F/g to about 300 F/g,about 200 F/g to about 400 F/g, about 200 F/g to about 500 F/g, about200 F/g to about 600 F/g, about 200 F/g to about 700 F/g, about 200 F/gto about 800 F/g, about 200 F/g to about 900 F/g, about 300 F/g to about400 F/g, about 300 F/g to about 500 F/g, about 300 F/g to about 600 F/g,about 300 F/g to about 700 F/g, about 300 F/g to about 800 F/g, about300 F/g to about 900 F/g, about 400 F/g to about 500 F/g, about 400 F/gto about 600 F/g, about 400 F/g to about 700 F/g, about 400 F/g to about800 F/g, about 400 F/g to about 900 F/g, about 500 F/g to about 600 F/g,about 500 F/g to about 700 F/g, about 500 F/g to about 800 F/g, about500 F/g to about 900 F/g, about 600 F/g to about 700 F/g, about 600 F/gto about 800 F/g, about 600 F/g to about 900 F/g, about 700 F/g to about800 F/g, about 700 F/g to about 900 F/g, or about 800 F/g to about 900F/g.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 20 A/g, of about 150 F/g to about 700 F/g.In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 20 A/g, of at least about 150 F/g. Inthose embodiments, the supercapacitor has a gravimetric capacitance, ina current density of about 20 A/g, of at most about 700 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 20 A/g, of about 150 F/g to about 250 F/g,about 150 F/g to about 350 F/g, about 150 F/g to about 450 F/g, about150 F/g to about 550 F/g, about 150 F/g to about 650 F/g, about 150 F/gto about 700 F/g, about 250 F/g to about 350 F/g, about 250 F/g to about450 F/g, about 250 F/g to about 550 F/g, about 250 F/g to about 650 F/g,about 250 F/g to about 700 F/g, about 350 F/g to about 450 F/g, about350 F/g to about 550 F/g, about 350 F/g to about 650 F/g, about 350 F/gto about 700 F/g, about 450 F/g to about 550 F/g, about 450 F/g to about650 F/g, about 450 F/g to about 700 F/g, about 550 F/g to about 650 F/g,about 550 F/g to about 700 F/g, or about 650 F/g to about 700 F/g.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 50 A/g, of about 125 F/g to about 600 F/g.In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 50 A/g, of at least about 125 F/g. Inthose embodiments, the supercapacitor has a gravimetric capacitance, ina current density of about 50 A/g, of at least about 600 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 50 A/g, of about 125 F/g to about 150 F/g,about 125 F/g to about 200 F/g, about 125 F/g to about 300 F/g, about125 F/g to about 400 F/g, about 125 F/g to about 500 F/g, about 125 F/gto about 600 F/g, about 150 F/g to about 200 F/g, about 150 F/g to about300 F/g, about 150 F/g to about 400 F/g, about 150 F/g to about 500 F/g,about 150 F/g to about 600 F/g, about 200 F/g to about 300 F/g, about200 F/g to about 400 F/g, about 200 F/g to about 500 F/g, about 200 F/gto about 600 F/g, about 300 F/g to about 400 F/g, about 300 F/g to about500 F/g, about 300 F/g to about 600 F/g, about 400 F/g to about 500 F/g,about 400 F/g to about 600 F/g, or about 500 F/g to about 600 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity of about 30 watt hours per kilogram (Wh/kg) to about 120 Wh/kg.In those embodiments, the supercapacitor has a gravimetric energydensity of at least about 30 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of at most about 120Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity of about 30 Wh/kg to about 40 Wh/kg, about 30 Wh/kg to about 50Wh/kg, about 30 Wh/kg to about 60 Wh/kg, about 30 Wh/kg to about 70Wh/kg, about 30 Wh/kg to about 80 Wh/kg, about 30 Wh/kg to about 100Wh/kg, about 30 Wh/kg to about 120 Wh/kg, about 40 Wh/kg to about 50Wh/kg, about 40 Wh/kg to about 60 Wh/kg, about 40 Wh/kg to about 70Wh/kg, about 40 Wh/kg to about 80 Wh/kg, about 40 Wh/kg to about 100Wh/kg, about 40 Wh/kg to about 120 Wh/kg, about 50 Wh/kg to about 60Wh/kg, about 50 Wh/kg to about 70 Wh/kg, about 50 Wh/kg to about 80Wh/kg, about 50 Wh/kg to about 100 Wh/kg, about 50 Wh/kg to about 120Wh/kg, about 60 Wh/kg to about 70 Wh/kg, about 60 Wh/kg to about 80Wh/kg, about 60 Wh/kg to about 100 Wh/kg, about 60 Wh/kg to about 120Wh/kg, about 70 Wh/kg to about 80 Wh/kg, about 70 Wh/kg to about 100Wh/kg, about 70 Wh/kg to about 120 Wh/kg, about 80 Wh/kg to about 100Wh/kg, about 80 Wh/kg to about 120 Wh/kg, or about 100 Wh/kg to about120 Wh/kg.

In some embodiments, the electrolyte is aqueous and further comprises aquinone wherein the quinone comprises 1,2-Benzoquinone;1,4-Benzoquinone; 1,4-Naphthoquinone; 9,10-Anthraquinone; or anycombination thereof.

In those embodiments, the quinone has a concentration of about 0.25 M toabout 1 M. In those embodiments, the quinone has a concentration of atleast about 0.25 M. In those embodiments, the quinone has aconcentration of at most about 1 M. In those embodiments, the quinonehas a concentration of about 0.25 M to about 0.375 M, about 0.25 M toabout 0.5 M, about 0.25 M to about 0.625 M, about 0.25 M to about 1 M,about 0.375 M to about 0.5 M, about 0.375 M to about 0.625 M, about0.375 M to about 1 M, about 0.5 M to about 0.625 M, about 0.5 M to about1 M, or about 0.625 M to about 1 M.

In those embodiments, the supercapacitor has a working potential ofabout 0.4 V to about 1.2 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.4 V. In those embodiments, thesupercapacitor has a working potential of at most about 1.2 V In thoseembodiments, the supercapacitor has a working potential of about 0.4 Vto about 0.5 V, about 0.4 V to about 0.6 V, about 0.4 V to about 0.7 V,about 0.4 V to about 0.8 V, about 0.4 V to about 0.9 V, about 0.4 V toabout 1 V, about 0.4 V to about 1.1 V, about 0.4 V to about 1.2 V, about0.5 V to about 0.6 V, about 0.5 V to about 0.7 V, about 0.5 V to about0.8 V, about 0.5 V to about 0.9 V, about 0.5 V to about 1 V, about 0.5 Vto about 1.1 V, about 0.5 V to about 1.2 V, about 0.6 V to about 0.7 V,about 0.6 V to about 0.8 V, about 0.6 V to about 0.9 V, about 0.6 V toabout 1 V, about 0.6 V to about 1.1 V, about 0.6 V to about 1.2 V, about0.7 V to about 0.8 V, about 0.7 V to about 0.9 V, about 0.7 V to about 1V, about 0.7 V to about 1.1 V, about 0.7 V to about 1.2 V, about 0.8 Vto about 0.9 V, about 0.8 V to about 1 V, about 0.8 V to about 1.1 V,about 0.8 V to about 1.2 V, about 0.9 V to about 1 V, about 0.9 V toabout 1.1 V, about 0.9 V to about 1.2 V, about 1 V to about 1.1 V, about1 V to about 1.2 V, or about 1.1 V to about 1.2 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 0.2 A/g, of about 300 F/g to about 1,400F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 0.2 A/g, of at least about300 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 0.2 A/g, of at most about11,400 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 0.2 A/g, of about 300 F/g toabout 500 F/g, about 300 F/g to about 700 F/g, about 300 F/g to about900 F/g, about 300 F/g to about 1,100 F/g, about 300 F/g to about 1,400F/g, about 500 F/g to about 700 F/g, about 500 F/g to about 900 F/g,about 500 F/g to about 1,100 F/g, about 500 F/g to about 1,400 F/g,about 700 F/g to about 900 F/g, about 700 F/g to about 1,100 F/g, about700 F/g to about 1,400 F/g, about 900 F/g to about 1,100 F/g, about 900F/g to about 1,400 F/g, or about 1,100 F/g to about 1,400 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity of about 12 Wh/kg to about 120 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of at least about 12Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity of at most about 120 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of about 12 Wh/kg toabout 20 Wh/kg, about 12 Wh/kg to about 40 Wh/kg, about 12 Wh/kg toabout 60 Wh/kg, about 12 Wh/kg to about 80 Wh/kg, about 12 Wh/kg toabout 100 Wh/kg, about 12 Wh/kg to about 120 Wh/kg, about 20 Wh/kg toabout 40 Wh/kg, about 20 Wh/kg to about 60 Wh/kg, about 20 Wh/kg toabout 80 Wh/kg, about 20 Wh/kg to about 100 Wh/kg, about 20 Wh/kg toabout 120 Wh/kg, about 40 Wh/kg to about 60 Wh/kg, about 40 Wh/kg toabout 80 Wh/kg, about 40 Wh/kg to about 100 Wh/kg, about 40 Wh/kg toabout 120 Wh/kg, about 60 Wh/kg to about 80 Wh/kg, about 60 Wh/kg toabout 100 Wh/kg, about 60 Wh/kg to about 120 Wh/kg, about 80 Wh/kg toabout 100 Wh/kg, about 80 Wh/kg to about 120 Wh/kg, or about 100 Wh/kgto about 120 Wh/kg.

In some embodiments, the electrolyte is a gel and further comprises aquinone comprising 1,2-Benzoquinone, 1,4-Benzoquinone,1,4-Naphthoquinone, 9,10-Anthraquinone or any combination thereof.

In those embodiments, the concentration of the quinone is about 5millimolar (mM) to about 20 millimolar. In those embodiments, theconcentration of the quinone is at least about 5 millimolar. In thoseembodiments, the concentration of the quinone is at most about 20millimolar. In those embodiments, the concentration of the quinone isabout 5 millimolar to about 7 millimolar, about 5 millimolar to about 9millimolar, about 5 millimolar to about 11 millimolar, about 5millimolar to about 13 millimolar, about 5 millimolar to about 15millimolar, about 5 millimolar to about 20 millimolar, about 7millimolar to about 9 millimolar, about 7 millimolar to about 11millimolar, about 7 millimolar to about 13 millimolar, about 7millimolar to about 15 millimolar, about 7 millimolar to about 20millimolar, about 9 millimolar to about 11 millimolar, about 9millimolar to about 13 millimolar, about 9 millimolar to about 15millimolar, about 9 millimolar to about 20 millimolar, about 11millimolar to about 13 millimolar, about 11 millimolar to about 15millimolar, about 11 millimolar to about 20 millimolar, about 13millimolar to about 15 millimolar, about 13 millimolar to about 20millimolar, or about 15 millimolar to about 20 millimolar.

In those embodiments, the supercapacitor has a working potential ofabout 0.4 V to about 1.6 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.4 V. In those embodiments, thesupercapacitor has a working potential of at most about 0.4 V. In thoseembodiments, the supercapacitor has a working potential of about 0.4 Vto about 0.5 V, about 0.4 V to about 0.6 V, about 0.4 V to about 0.7 V,about 0.4 V to about 0.8 V, about 0.4 V to about 0.9 V, about 0.4 V toabout 1 V, about 0.4 V to about 1.2 V, about 0.4 V to about 1.4 V, about0.4 V to about 1.6 V, about 0.5 V to about 0.6 V, about 0.5 V to about0.7 V, about 0.5 V to about 0.8 V, about 0.5 V to about 0.9 V, about 0.5V to about 1 V, about 0.5 V to about 1.2 V, about 0.5 V to about 1.4 V,about 0.5 V to about 1.6 V, about 0.6 V to about 0.7 V, about 0.6 V toabout 0.8 V, about 0.6 V to about 0.9 V, about 0.6 V to about 1 V, about0.6 V to about 1.2 V, about 0.6 V to about 1.4 V, about 0.6 V to about1.6 V, about 0.7 V to about 0.8 V, about 0.7 V to about 0.9 V, about 0.7V to about 1 V, about 0.7 V to about 1.2 V, about 0.7 V to about 1.4 V,about 0.7 V to about 1.6 V, about 0.8 V to about 0.9 V, about 0.8 V toabout 1 V, about 0.8 V to about 1.2 V, about 0.8 V to about 1.4 V, about0.8 V to about 1.6 V, about 0.9 V to about 1 V, about 0.9 V to about 1.2V, about 0.9 V to about 1.4 V, about 0.9 V to about 1.6 V, about 1 V toabout 1.2 V, about 1 V to about 1.4 V, about 1 V to about 1.6 V, about1.2 V to about 1.4 V, about 1.2 V to about 1.6 V, or about 1.4 V toabout 1.6 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of about 350 F/g to about 1,400F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of at least about 350F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of at most about 1,400F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of about 350 F/g toabout 450 F/g, about 350 F/g to about 550 F/g, about 350 F/g to about650 F/g, about 350 F/g to about 750 F/g, about 350 F/g to about 850 F/g,about 350 F/g to about 1,000 F/g, about 350 F/g to about 1,200 F/g,about 350 F/g to about 1,400 F/g, about 450 F/g to about 550 F/g, about450 F/g to about 650 F/g, about 450 F/g to about 750 F/g, about 450 F/gto about 850 F/g, about 450 F/g to about 1,000 F/g, about 450 F/g toabout 1,200 F/g, about 450 F/g to about 1,400 F/g, about 550 F/g toabout 650 F/g, about 550 F/g to about 750 F/g, about 550 F/g to about850 F/g, about 550 F/g to about 1,000 F/g, about 550 F/g to about 1,200F/g, about 550 F/g to about 1,400 F/g, about 650 F/g to about 750 F/g,about 650 F/g to about 850 F/g, about 650 F/g to about 1,000 F/g, about650 F/g to about 1,200 F/g, about 650 F/g to about 1,400 F/g, about 750F/g to about 850 F/g, about 750 F/g to about 1,000 F/g, about 750 F/g toabout 1,200 F/g, about 750 F/g to about 1,400 F/g, about 850 F/g toabout 1,000 F/g, about 850 F/g to about 1,200 F/g, about 850 F/g toabout 1,400 F/g, about 1,000 F/g to about 1,200 F/g, about 1,000 F/g toabout 1,400 F/g, or about 1,200 F/g to about 1,400 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity of about 30 Wh/kg to about 130 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of at least about 30Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity of at most about 130 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of about 30 Wh/kg toabout 40 Wh/kg, about 30 Wh/kg to about 50 Wh/kg, about 30 Wh/kg toabout 60 Wh/kg, about 30 Wh/kg to about 70 Wh/kg, about 30 Wh/kg toabout 80 Wh/kg, about 30 Wh/kg to about 100 Wh/kg, about 30 Wh/kg toabout 120 Wh/kg, about 30 Wh/kg to about 130 Wh/kg, about 40 Wh/kg toabout 50 Wh/kg, about 40 Wh/kg to about 60 Wh/kg, about 40 Wh/kg toabout 70 Wh/kg, about 40 Wh/kg to about 80 Wh/kg, about 40 Wh/kg toabout 100 Wh/kg, about 40 Wh/kg to about 120 Wh/kg, about 40 Wh/kg toabout 130 Wh/kg, about 50 Wh/kg to about 60 Wh/kg, about 50 Wh/kg toabout 70 Wh/kg, about 50 Wh/kg to about 80 Wh/kg, about 50 Wh/kg toabout 100 Wh/kg, about 50 Wh/kg to about 120 Wh/kg, about 50 Wh/kg toabout 130 Wh/kg, about 60 Wh/kg to about 70 Wh/kg, about 60 Wh/kg toabout 80 Wh/kg, about 60 Wh/kg to about 100 Wh/kg, about 60 Wh/kg toabout 120 Wh/kg, about 60 Wh/kg to about 130 Wh/kg, about 70 Wh/kg toabout 80 Wh/kg, about 70 Wh/kg to about 100 Wh/kg, about 70 Wh/kg toabout 120 Wh/kg, about 70 Wh/kg to about 130 Wh/kg, about 80 Wh/kg toabout 100 Wh/kg, about 80 Wh/kg to about 120 Wh/kg, about 80 Wh/kg toabout 130 Wh/kg, about 100 Wh/kg to about 120 Wh/kg, about 100 Wh/kg toabout 130 Wh/kg, or about 120 Wh/kg to about 130 Wh/kg.

In some embodiments, the supercapacitor further comprises a thirdfunctionalized carbon electrode. In some embodiments the thirdfunctionalized carbon electrode is a polyaniline functionalized carbonelectrode.

In some embodiments, the electrolyte is disposed between the electrodes.In some embodiments, the electrolyte comprises an acid. In someembodiments, the electrolyte comprises a solvent. In some embodiments,the electrolyte comprises an acid and a solvent. In some embodiments,the acid is a strong acid. In some embodiments, the strong acidcomprises perchloric acid, hydroiodic acid, hydrobromic acid,hydrochloric acid, sulfuric acid, p-toluenesulfonic acid methanesulfonicacid, or any combination thereof. In some embodiments, the solventcomprises tetrahydrofuran, ethyl acetate, dimethylformamide,acetonitrile, acetone, dimethyl sulfoxide, nitromethane, propylenecarbonate, ethanol, formic acid, n-butanol, methanol, acetic acid,water, or any combination thereof. In some embodiments the concentrationof the acid has a great influence on the structure and properties ofpolyaniline (PANI).

In those embodiments, the concentration of the quinone is about 0.25millimolar to about 1 millimolar. In those embodiments, theconcentration of the quinone is at least about 0.25 millimolar. In thoseembodiments, the concentration of the quinone is at most about 1millimolar. In those embodiments, the concentration of the quinone isabout 0.25 millimolar to about 0.375 millimolar, about 0.25 millimolarto about 0.5 millimolar, about 0.25 millimolar to about 0.625millimolar, about 0.25 millimolar to about 0.75 millimolar, about 0.25millimolar to about 1 millimolar, about 0.375 millimolar to about 0.5millimolar, about 0.375 millimolar to about 0.625 millimolar, about0.375 millimolar to about 0.75 millimolar, about 0.375 millimolar toabout 1 millimolar, about 0.5 millimolar to about 0.625 millimolar,about 0.5 millimolar to about 0.75 millimolar, about 0.5 millimolar toabout 1 millimolar, about 0.625 millimolar to about 0.75 millimolar,about 0.625 millimolar to about 1 millimolar, or about 0.75 millimolarto about 1 millimolar.

In those embodiments, the supercapacitor has a working potential ofabout 0.1 V to about 1.6 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.1 V. In those embodiments, thesupercapacitor has a working potential of at most about 1.6 V. In thoseembodiments, the supercapacitor has a working potential of about 0.1 Vto about 0.2 V, about 0.1 V to about 0.3 V, about 0.1 V to about 0.4 V,about 0.1 V to about 0.6 V, about 0.1 V to about 0.8 V, about 0.1 V toabout 1 V, about 0.1 V to about 1.2 V, about 0.1 V to about 1.4 V, about0.1 V to about 1.6 V, about 0.2 V to about 0.3 V, about 0.2 V to about0.4 V, about 0.2 V to about 0.6 V, about 0.2 V to about 0.8 V, about 0.2V to about 1 V, about 0.2 V to about 1.2 V, about 0.2 V to about 1.4 V,about 0.2 V to about 1.6 V, about 0.3 V to about 0.4 V, about 0.3 V toabout 0.6 V, about 0.3 V to about 0.8 V, about 0.3 V to about 1 V, about0.3 V to about 1.2 V, about 0.3 V to about 1.4 V, about 0.3 V to about1.6 V, about 0.4 V to about 0.6 V, about 0.4 V to about 0.8 V, about 0.4V to about 1 V, about 0.4 V to about 1.2 V, about 0.4 V to about 1.4 V,about 0.4 V to about 1.6 V, about 0.6 V to about 0.8 V, about 0.6 V toabout 1 V, about 0.6 V to about 1.2 V, about 0.6 V to about 1.4 V, about0.6 V to about 1.6 V, about 0.8 V to about 1 V, about 0.8 V to about 1.2V, about 0.8 V to about 1.4 V, about 0.8 V to about 1.6 V, about 1 V toabout 1.2 V, about 1 V to about 1.4 V, about 1 V to about 1.6 V, about1.2 V to about 1.4 V, about 1.2 V to about 1.6 V, or about 1.4 V toabout 1.6 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 10 A/g, of about 5,000 F/g to about 20,000F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 10 A/g, of at least about5,000 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 10 A/g, of at most about20,000 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 10 A/g, of about 5,000 F/g toabout 6,000 F/g, about 5,000 F/g to about 7,000 F/g, about 5,000 F/g toabout 8,000 F/g, about 5,000 F/g to about 9,000 F/g, about 5,000 F/g toabout 10,000 F/g, about 5,000 F/g to about 12,500 F/g, about 5,000 F/gto about 15,000 F/g, about 5,000 F/g to about 17,500 F/g, about 5,000F/g to about 20,000 F/g, about 6,000 F/g to about 7,000 F/g, about 6,000F/g to about 8,000 F/g, about 6,000 F/g to about 9,000 F/g, about 6,000F/g to about 10,000 F/g, about 6,000 F/g to about 12,500 F/g, about6,000 F/g to about 15,000 F/g, about 6,000 F/g to about 17,500 F/g,about 6,000 F/g to about 20,000 F/g, about 7,000 F/g to about 8,000 F/g,about 7,000 F/g to about 9,000 F/g, about 7,000 F/g to about 10,000 F/g,about 7,000 F/g to about 12,500 F/g, about 7,000 F/g to about 15,000F/g, about 7,000 F/g to about 17,500 F/g, about 7,000 F/g to about20,000 F/g, about 8,000 F/g to about 9,000 F/g, about 8,000 F/g to about10,000 F/g, about 8,000 F/g to about 12,500 F/g, about 8,000 F/g toabout 15,000 F/g, about 8,000 F/g to about 17,500 F/g, about 8,000 F/gto about 20,000 F/g, about 9,000 F/g to about 10,000 F/g, about 9,000F/g to about 12,500 F/g, about 9,000 F/g to about 15,000 F/g, about9,000 F/g to about 17,500 F/g, about 9,000 F/g to about 20,000 F/g,about 10,000 F/g to about 12,500 F/g, about 10,000 F/g to about 15,000F/g, about 10,000 F/g to about 17,500 F/g, about 10,000 F/g to about20,000 F/g, about 12,500 F/g to about 15,000 F/g, about 12,500 F/g toabout 17,500 F/g, about 12,500 F/g to about 20,000 F/g, about 15,000 F/gto about 17,500 F/g, about 15,000 F/g to about 20,000 F/g, or about17,500 F/g to about 20,000 F/g.

A third aspect disclosed herein is a supercapacitor comprising two ormore electrodes, wherein the first electrode comprises a functionalizedcarbon electrode and the second electrode comprises an activated carbonelectrode; a current collector; and an electrolyte. In some embodiments,the current collector is metallic. In some embodiments, thefunctionalized carbon electrode is a polyaniline functionalized carbonelectrode. In some embodiments, the current collector is ferritic. Insome embodiments, the current collector comprises stainless steel,crucible steel, carbon steel, spring steel, alloy steel, maraging steel,weathering steel, tool steel, or any combination thereof.

In some embodiments, the electrolyte is disposed between the firstfunctionalized carbon electrode and the second functionalized carbonelectrode. In some embodiments, the electrolyte comprises an acid. Insome embodiments, the electrolyte comprises a solvent. In someembodiments, the electrolyte comprises an acid and a solvent. In someembodiments, the acid is a strong acid. In some embodiments, the strongacid comprises perchloric acid, hydroiodic acid, hydrobromic acid,hydrochloric acid, sulfuric acid, p-toluenesulfonic acid methanesulfonicacid, or any combination thereof. In some embodiments, the solventcomprises tetrahydrofuran, ethyl acetate, dimethylformamide,acetonitrile, acetone, dimethyl sulfoxide, nitromethane, propylenecarbonate, ethanol, formic acid, n-butanol, methanol, acetic acid,water, or any combination thereof.

In some embodiments the electrolyte is an aqueous electrolyte.

In those embodiments, the supercapacitor has a working potential ofabout 0.6 V to about 2.6 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.6 V. In those embodiments, thesupercapacitor has a working potential of at most about 2.6 V. In thoseembodiments, the supercapacitor has a working potential of about 0.6 Vto about 0.8 V, about 0.6 V to about 1 V, about 0.6 V to about 1.2 V,about 0.6 V to about 1.4 V, about 0.6 V to about 1.6 V, about 0.6 V toabout 1.8 V, about 0.6 V to about 2 V, about 0.6 V to about 2.2 V, about0.6 V to about 2.4 V, about 0.6 V to about 2.6 V, about 0.8 V to about 1V, about 0.8 V to about 1.2 V, about 0.8 V to about 1.4 V, about 0.8 Vto about 1.6 V, about 0.8 V to about 1.8 V, about 0.8 V to about 2 V,about 0.8 V to about 2.2 V, about 0.8 V to about 2.4 V, about 0.8 V toabout 2.6 V, about 1 V to about 1.2 V, about 1 V to about 1.4 V, about 1V to about 1.6 V, about 1 V to about 1.8 V, about 1 V to about 2 V,about 1 V to about 2.2 V, about 1 V to about 2.4 V, about 1 V to about2.6 V, about 1.2 V to about 1.4 V, about 1.2 V to about 1.6 V, about 1.2V to about 1.8 V, about 1.2 V to about 2 V, about 1.2 V to about 2.2 V,about 1.2 V to about 2.4 V, about 1.2 V to about 2.6 V, about 1.4 V toabout 1.6 V, about 1.4 V to about 1.8 V, about 1.4 V to about 2 V, about1.4 V to about 2.2 V, about 1.4 V to about 2.4 V, about 1.4 V to about2.6 V, about 1.6 V to about 1.8 V, about 1.6 V to about 2 V, about 1.6 Vto about 2.2 V, about 1.6 V to about 2.4 V, about 1.6 V to about 2.6 V,about 1.8 V to about 2 V, about 1.8 V to about 2.2 V, about 1.8 V toabout 2.4 V, about 1.8 V to about 2.6 V, about 2 V to about 2.2 V, about2 V to about 2.4 V, about 2 V to about 2.6 V, about 2.2 V to about 2.4V, about 2.2 V to about 2.6 V, or about 2.4 V to about 2.6 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of about 150 F/g to about 600 F/g.In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of at least about 150 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 2 A/g, of at most about 600 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 2 A/g, of about 150 F/g to about 200 F/g, about150 F/g to about 250 F/g, about 150 F/g to about 300 F/g, about 150 F/gto about 350 F/g, about 150 F/g to about 400 F/g, about 150 F/g to about450 F/g, about 150 F/g to about 500 F/g, about 150 F/g to about 550 F/g,about 150 F/g to about 600 F/g, about 200 F/g to about 250 F/g, about200 F/g to about 300 F/g, about 200 F/g to about 350 F/g, about 200 F/gto about 400 F/g, about 200 F/g to about 450 F/g, about 200 F/g to about500 F/g, about 200 F/g to about 550 F/g, about 200 F/g to about 600 F/g,about 250 F/g to about 300 F/g, about 250 F/g to about 350 F/g, about250 F/g to about 400 F/g, about 250 F/g to about 450 F/g, about 250 F/gto about 500 F/g, about 250 F/g to about 550 F/g, about 250 F/g to about600 F/g, about 300 F/g to about 350 F/g, about 300 F/g to about 400 F/g,about 300 F/g to about 450 F/g, about 300 F/g to about 500 F/g, about300 F/g to about 550 F/g, about 300 F/g to about 600 F/g, about 350 F/gto about 400 F/g, about 350 F/g to about 450 F/g, about 350 F/g to about500 F/g, about 350 F/g to about 550 F/g, about 350 F/g to about 600 F/g,about 400 F/g to about 450 F/g, about 400 F/g to about 500 F/g, about400 F/g to about 550 F/g, about 400 F/g to about 600 F/g, about 450 F/gto about 500 F/g, about 450 F/g to about 550 F/g, about 450 F/g to about600 F/g, about 500 F/g to about 550 F/g, about 500 F/g to about 600 F/g,or about 550 F/g to about 600 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity of about 45 Wh/kg to about 180 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of at least about 45Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity of at most about 180 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of about 45 Wh/kg toabout 60 Wh/kg, about 45 Wh/kg to about 80 Wh/kg, about 45 Wh/kg toabout 100 Wh/kg, about 45 Wh/kg to about 120 Wh/kg, about 45 Wh/kg toabout 140 Wh/kg, about 45 Wh/kg to about 160 Wh/kg, about 45 Wh/kg toabout 180 Wh/kg, about 60 Wh/kg to about 80 Wh/kg, about 60 Wh/kg toabout 100 Wh/kg, about 60 Wh/kg to about 120 Wh/kg, about 60 Wh/kg toabout 140 Wh/kg, about 60 Wh/kg to about 160 Wh/kg, about 60 Wh/kg toabout 180 Wh/kg, about 80 Wh/kg to about 100 Wh/kg, about 80 Wh/kg toabout 120 Wh/kg, about 80 Wh/kg to about 140 Wh/kg, about 80 Wh/kg toabout 160 Wh/kg, about 80 Wh/kg to about 180 Wh/kg, about 100 Wh/kg toabout 120 Wh/kg, about 100 Wh/kg to about 140 Wh/kg, about 100 Wh/kg toabout 160 Wh/kg, about 100 Wh/kg to about 180 Wh/kg, about 120 Wh/kg toabout 140 Wh/kg, about 120 Wh/kg to about 160 Wh/kg, about 120 Wh/kg toabout 180 Wh/kg, about 140 Wh/kg to about 160 Wh/kg, about 140 Wh/kg toabout 180 Wh/kg, or about 160 Wh/kg to about 180 Wh/kg.

In some embodiments, the aqueous electrolyte comprises a quinone.

In those embodiments, the concentration of the quinone is about 0.25millimolar to about 1 millimolar. In those embodiments, theconcentration of the quinone is at least about 0.25 millimolar. In thoseembodiments, the concentration of the quinone is at most about 1millimolar. In those embodiments, the concentration of the quinone isabout 0.25 millimolar to about 0.375 millimolar, about 0.25 millimolarto about 0.5 millimolar, about 0.25 millimolar to about 0.625millimolar, about 0.25 millimolar to about 0.75 millimolar, about 0.25millimolar to about 1 millimolar, about 0.375 millimolar to about 0.5millimolar, about 0.375 millimolar to about 0.625 millimolar, about0.375 millimolar to about 0.75 millimolar, about 0.375 millimolar toabout 1 millimolar, about 0.5 millimolar to about 0.625 millimolar,about 0.5 millimolar to about 0.75 millimolar, about 0.5 millimolar toabout 1 millimolar, about 0.625 millimolar to about 0.75 millimolar,about 0.625 millimolar to about 1 millimolar, or about 0.75 millimolarto about 1 millimolar.

In those embodiments, the supercapacitor has a working potential ofabout 0.6 V to about 3.5 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.6 V. In those embodiments, thesupercapacitor has a working potential of at most about 3.5 V. In thoseembodiments, the supercapacitor has a working potential of about 0.6 Vto about 0.8 V, about 0.6 V to about 1 V, about 0.6 V to about 1.2 V,about 0.6 V to about 1.4 V, about 0.6 V to about 1.6 V, about 0.6 V toabout 1.8 V, about 0.6 V to about 2 V, about 0.6 V to about 2.5 V, about0.6 V to about 3 V, about 0.6 V to about 3.5 V, about 0.8 V to about 1V, about 0.8 V to about 1.2 V, about 0.8 V to about 1.4 V, about 0.8 Vto about 1.6 V, about 0.8 V to about 1.8 V, about 0.8 V to about 2 V,about 0.8 V to about 2.5 V, about 0.8 V to about 3 V, about 0.8 V toabout 3.5 V, about 1 V to about 1.2 V, about 1 V to about 1.4 V, about 1V to about 1.6 V, about 1 V to about 1.8 V, about 1 V to about 2 V,about 1 V to about 2.5 V, about 1 V to about 3 V, about 1 V to about 3.5V, about 1.2 V to about 1.4 V, about 1.2 V to about 1.6 V, about 1.2 Vto about 1.8 V, about 1.2 V to about 2 V, about 1.2 V to about 2.5 V,about 1.2 V to about 3 V, about 1.2 V to about 3.5 V, about 1.4 V toabout 1.6 V, about 1.4 V to about 1.8 V, about 1.4 V to about 2 V, about1.4 V to about 2.5 V, about 1.4 V to about 3 V, about 1.4 V to about 3.5V, about 1.6 V to about 1.8 V, about 1.6 V to about 2 V, about 1.6 V toabout 2.5 V, about 1.6 V to about 3 V, about 1.6 V to about 3.5 V, about1.8 V to about 2 V, about 1.8 V to about 2.5 V, about 1.8 V to about 3V, about 1.8 V to about 3.5 V, about 2 V to about 2.5 V, about 2 V toabout 3 V, about 2 V to about 3.5 V, about 2.5 V to about 3 V, about 2.5V to about 3.5 V, or about 3 V to about 3.5 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of about 150 F/g to about 700 F/g.In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of at least about 150 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 2 A/g, of at most about 700 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 2 A/g, of about 150 F/g to about 200 F/g, about150 F/g to about 250 F/g, about 150 F/g to about 300 F/g, about 150 F/gto about 350 F/g, about 150 F/g to about 400 F/g, about 150 F/g to about450 F/g, about 150 F/g to about 500 F/g, about 150 F/g to about 600 F/g,about 150 F/g to about 700 F/g, about 200 F/g to about 250 F/g, about200 F/g to about 300 F/g, about 200 F/g to about 350 F/g, about 200 F/gto about 400 F/g, about 200 F/g to about 450 F/g, about 200 F/g to about500 F/g, about 200 F/g to about 600 F/g, about 200 F/g to about 700 F/g,about 250 F/g to about 300 F/g, about 250 F/g to about 350 F/g, about250 F/g to about 400 F/g, about 250 F/g to about 450 F/g, about 250 F/gto about 500 F/g, about 250 F/g to about 600 F/g, about 250 F/g to about700 F/g, about 300 F/g to about 350 F/g, about 300 F/g to about 400 F/g,about 300 F/g to about 450 F/g, about 300 F/g to about 500 F/g, about300 F/g to about 600 F/g, about 300 F/g to about 700 F/g, about 350 F/gto about 400 F/g, about 350 F/g to about 450 F/g, about 350 F/g to about500 F/g, about 350 F/g to about 600 F/g, about 350 F/g to about 700 F/g,about 400 F/g to about 450 F/g, about 400 F/g to about 500 F/g, about400 F/g to about 600 F/g, about 400 F/g to about 700 F/g, about 450 F/gto about 500 F/g, about 450 F/g to about 600 F/g, about 450 F/g to about700 F/g, about 500 F/g to about 600 F/g, about 500 F/g to about 700 F/g,or about 600 F/g to about 700 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity of about 40 Wh/kg to about 1,600 Wh/kg. In those embodiments,the supercapacitor has a gravimetric energy density of at least about 40Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity of at most about 1,600 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of about 40 Wh/kg toabout 50 Wh/kg, about 40 Wh/kg to about 100 Wh/kg, about 40 Wh/kg toabout 250 Wh/kg, about 40 Wh/kg to about 500 Wh/kg, about 40 Wh/kg toabout 750 Wh/kg, about 40 Wh/kg to about 1,000 Wh/kg, about 40 Wh/kg toabout 1,250 Wh/kg, about 40 Wh/kg to about 1,600 Wh/kg, about 50 Wh/kgto about 100 Wh/kg, about 50 Wh/kg to about 250 Wh/kg, about 50 Wh/kg toabout 500 Wh/kg, about 50 Wh/kg to about 750 Wh/kg, about 50 Wh/kg toabout 1,000 Wh/kg, about 50 Wh/kg to about 1,250 Wh/kg, about 50 Wh/kgto about 1,600 Wh/kg, about 100 Wh/kg to about 250 Wh/kg, about 100Wh/kg to about 500 Wh/kg, about 100 Wh/kg to about 750 Wh/kg, about 100Wh/kg to about 1,000 Wh/kg, about 100 Wh/kg to about 1,250 Wh/kg, about100 Wh/kg to about 1,600 Wh/kg, about 250 Wh/kg to about 500 Wh/kg,about 250 Wh/kg to about 750 Wh/kg, about 250 Wh/kg to about 1,000Wh/kg, about 250 Wh/kg to about 1,250 Wh/kg, about 250 Wh/kg to about1,600 Wh/kg, about 500 Wh/kg to about 750 Wh/kg, about 500 Wh/kg toabout 1,000 Wh/kg, about 500 Wh/kg to about 1,250 Wh/kg, about 500 Wh/kgto about 1,600 Wh/kg, about 750 Wh/kg to about 1,000 Wh/kg, about 750Wh/kg to about 1,250 Wh/kg, about 750 Wh/kg to about 1,600 Wh/kg, about1,000 Wh/kg to about 1,250 Wh/kg, about 1,000 Wh/kg to about 1,600Wh/kg, or about 1,250 Wh/kg to about 1,600 Wh/kg.

In some embodiments, the electrolyte is a gel electrolyte.

In those embodiments, the supercapacitor has a working potential ofabout 0.6 V to about 2.4 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.6 V. In those embodiments, thesupercapacitor has a working potential of at most about 2.4 V. In thoseembodiments, the supercapacitor has a working potential of about 0.6 Vto about 0.8 V, about 0.6 V to about 1 V, about 0.6 V to about 1.2 V,about 0.6 V to about 1.4 V, about 0.6 V to about 1.6 V, about 0.6 V toabout 1.8 V, about 0.6 V to about 2 V, about 0.6 V to about 2.2 V, about0.6 V to about 2.4 V, about 0.8 V to about 1 V, about 0.8 V to about 1.2V, about 0.8 V to about 1.4 V, about 0.8 V to about 1.6 V, about 0.8 Vto about 1.8 V, about 0.8 V to about 2 V, about 0.8 V to about 2.2 V,about 0.8 V to about 2.4 V, about 1 V to about 1.2 V, about 1 V to about1.4 V, about 1 V to about 1.6 V, about 1 V to about 1.8 V, about 1 V toabout 2 V, about 1 V to about 2.2 V, about 1 V to about 2.4 V, about 1.2V to about 1.4 V, about 1.2 V to about 1.6 V, about 1.2 V to about 1.8V, about 1.2 V to about 2 V, about 1.2 V to about 2.2 V, about 1.2 V toabout 2.4 V, about 1.4 V to about 1.6 V, about 1.4 V to about 1.8 V,about 1.4 V to about 2 V, about 1.4 V to about 2.2 V, about 1.4 V toabout 2.4 V, about 1.6 V to about 1.8 V, about 1.6 V to about 2 V, about1.6 V to about 2.2 V, about 1.6 V to about 2.4 V, about 1.8 V to about 2V, about 1.8 V to about 2.2 V, about 1.8 V to about 2.4 V, about 2 V toabout 2.2 V, about 2 V to about 2.4 V, or about 2.2 V to about 2.4 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of about 150 F/g to about 650 F/g.In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of at least about 150 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 2 A/g, of at most about 650 F/g. In thoseembodiments, the supercapacitor has a gravimetric capacitance, in acurrent density of about 2 A/g, of about 150 F/g to about 200 F/g, about150 F/g to about 250 F/g, about 150 F/g to about 300 F/g, about 150 F/gto about 350 F/g, about 150 F/g to about 400 F/g, about 150 F/g to about450 F/g, about 150 F/g to about 500 F/g, about 150 F/g to about 550 F/g,about 150 F/g to about 600 F/g, about 150 F/g to about 650 F/g, about200 F/g to about 250 F/g, about 200 F/g to about 300 F/g, about 200 F/gto about 350 F/g, about 200 F/g to about 400 F/g, about 200 F/g to about450 F/g, about 200 F/g to about 500 F/g, about 200 F/g to about 550 F/g,about 200 F/g to about 600 F/g, about 200 F/g to about 650 F/g, about250 F/g to about 300 F/g, about 250 F/g to about 350 F/g, about 250 F/gto about 400 F/g, about 250 F/g to about 450 F/g, about 250 F/g to about500 F/g, about 250 F/g to about 550 F/g, about 250 F/g to about 600 F/g,about 250 F/g to about 650 F/g, about 300 F/g to about 350 F/g, about300 F/g to about 400 F/g, about 300 F/g to about 450 F/g, about 300 F/gto about 500 F/g, about 300 F/g to about 550 F/g, about 300 F/g to about600 F/g, about 300 F/g to about 650 F/g, about 350 F/g to about 400 F/g,about 350 F/g to about 450 F/g, about 350 F/g to about 500 F/g, about350 F/g to about 550 F/g, about 350 F/g to about 600 F/g, about 350 F/gto about 650 F/g, about 400 F/g to about 450 F/g, about 400 F/g to about500 F/g, about 400 F/g to about 550 F/g, about 400 F/g to about 600 F/g,about 400 F/g to about 650 F/g, about 450 F/g to about 500 F/g, about450 F/g to about 550 F/g, about 450 F/g to about 600 F/g, about 450 F/gto about 650 F/g, about 500 F/g to about 550 F/g, about 500 F/g to about600 F/g, about 500 F/g to about 650 F/g, about 550 F/g to about 600 F/g,about 550 F/g to about 650 F/g, or about 600 F/g to about 650 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity of about 30 Wh/kg to about 130 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of at least about 30Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity of at most about 130 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density of about 30 Wh/kg toabout 40 Wh/kg, about 30 Wh/kg to about 50 Wh/kg, about 30 Wh/kg toabout 60 Wh/kg, about 30 Wh/kg to about 70 Wh/kg, about 30 Wh/kg toabout 80 Wh/kg, about 30 Wh/kg to about 90 Wh/kg, about 30 Wh/kg toabout 100 Wh/kg, about 30 Wh/kg to about 110 Wh/kg, about 30 Wh/kg toabout 120 Wh/kg, about 30 Wh/kg to about 130 Wh/kg, about 40 Wh/kg toabout 50 Wh/kg, about 40 Wh/kg to about 60 Wh/kg, about 40 Wh/kg toabout 70 Wh/kg, about 40 Wh/kg to about 80 Wh/kg, about 40 Wh/kg toabout 90 Wh/kg, about 40 Wh/kg to about 100 Wh/kg, about 40 Wh/kg toabout 110 Wh/kg, about 40 Wh/kg to about 120 Wh/kg, about 40 Wh/kg toabout 130 Wh/kg, about 50 Wh/kg to about 60 Wh/kg, about 50 Wh/kg toabout 70 Wh/kg, about 50 Wh/kg to about 80 Wh/kg, about 50 Wh/kg toabout 90 Wh/kg, about 50 Wh/kg to about 100 Wh/kg, about 50 Wh/kg toabout 110 Wh/kg, about 50 Wh/kg to about 120 Wh/kg, about 50 Wh/kg toabout 130 Wh/kg, about 60 Wh/kg to about 70 Wh/kg, about 60 Wh/kg toabout 80 Wh/kg, about 60 Wh/kg to about 90 Wh/kg, about 60 Wh/kg toabout 100 Wh/kg, about 60 Wh/kg to about 110 Wh/kg, about 60 Wh/kg toabout 120 Wh/kg, about 60 Wh/kg to about 130 Wh/kg, about 70 Wh/kg toabout 80 Wh/kg, about 70 Wh/kg to about 90 Wh/kg, about 70 Wh/kg toabout 100 Wh/kg, about 70 Wh/kg to about 110 Wh/kg, about 70 Wh/kg toabout 120 Wh/kg, about 70 Wh/kg to about 130 Wh/kg, about 80 Wh/kg toabout 90 Wh/kg, about 80 Wh/kg to about 100 Wh/kg, about 80 Wh/kg toabout 110 Wh/kg, about 80 Wh/kg to about 120 Wh/kg, about 80 Wh/kg toabout 130 Wh/kg, about 90 Wh/kg to about 100 Wh/kg, about 90 Wh/kg toabout 110 Wh/kg, about 90 Wh/kg to about 120 Wh/kg, about 90 Wh/kg toabout 130 Wh/kg, about 100 Wh/kg to about 110 Wh/kg, about 100 Wh/kg toabout 120 Wh/kg, about 100 Wh/kg to about 130 Wh/kg, about 110 Wh/kg toabout 120 Wh/kg, about 110 Wh/kg to about 130 Wh/kg, or about 120 Wh/kgto about 130 Wh/kg.

In some embodiments the gel electrolyte comprises a quinone.

In those embodiments, the concentration of the quinone is about 0.25millimolar to about 1 millimolar. In those embodiments, theconcentration of the quinone is at least about 0.25 millimolar. In thoseembodiments, the concentration of the quinone is at most about 1millimolar. In those embodiments, the concentration of the quinone isabout 0.25 millimolar to about 0.375 millimolar, about 0.25 millimolarto about 0.5 millimolar, about 0.25 millimolar to about 0.625millimolar, about 0.25 millimolar to about 0.75 millimolar, about 0.25millimolar to about 1 millimolar, about 0.375 millimolar to about 0.5millimolar, about 0.375 millimolar to about 0.625 millimolar, about0.375 millimolar to about 0.75 millimolar, about 0.375 millimolar toabout 1 millimolar, about 0.5 millimolar to about 0.625 millimolar,about 0.5 millimolar to about 0.75 millimolar, about 0.5 millimolar toabout 1 millimolar, about 0.625 millimolar to about 0.75 millimolar,about 0.625 millimolar to about 1 millimolar, or about 0.75 millimolarto about 1 millimolar.

In those embodiments, the supercapacitor has a working potential ofabout 0.7 V to about 2.8 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.7 V. In those embodiments, thesupercapacitor has a working potential of at most about 2.8 V. In thoseembodiments, the supercapacitor has a working potential of about 0.7 Vto about 0.8 V, about 0.7 V to about 1 V, about 0.7 V to about 1.2 V,about 0.7 V to about 1.4 V, about 0.7 V to about 1.6 V, about 0.7 V toabout 1.8 V, about 0.7 V to about 2 V, about 0.7 V to about 2.2 V, about0.7 V to about 2.4 V, about 0.7 V to about 2.6 V, about 0.7 V to about2.8 V, about 0.8 V to about 1 V, about 0.8 V to about 1.2 V, about 0.8 Vto about 1.4 V, about 0.8 V to about 1.6 V, about 0.8 V to about 1.8 V,about 0.8 V to about 2 V, about 0.8 V to about 2.2 V, about 0.8 V toabout 2.4 V, about 0.8 V to about 2.6 V, about 0.8 V to about 2.8 V,about 1 V to about 1.2 V, about 1 V to about 1.4 V, about 1 V to about1.6 V, about 1 V to about 1.8 V, about 1 V to about 2 V, about 1 V toabout 2.2 V, about 1 V to about 2.4 V, about 1 V to about 2.6 V, about 1V to about 2.8 V, about 1.2 V to about 1.4 V, about 1.2 V to about 1.6V, about 1.2 V to about 1.8 V, about 1.2 V to about 2 V, about 1.2 V toabout 2.2 V, about 1.2 V to about 2.4 V, about 1.2 V to about 2.6 V,about 1.2 V to about 2.8 V, about 1.4 V to about 1.6 V, about 1.4 V toabout 1.8 V, about 1.4 V to about 2 V, about 1.4 V to about 2.2 V, about1.4 V to about 2.4 V, about 1.4 V to about 2.6 V, about 1.4 V to about2.8 V, about 1.6 V to about 1.8 V, about 1.6 V to about 2 V, about 1.6 Vto about 2.2 V, about 1.6 V to about 2.4 V, about 1.6 V to about 2.6 V,about 1.6 V to about 2.8 V, about 1.8 V to about 2 V, about 1.8 V toabout 2.2 V, about 1.8 V to about 2.4 V, about 1.8 V to about 2.6 V,about 1.8 V to about 2.8 V, about 2 V to about 2.2 V, about 2 V to about2.4 V, about 2 V to about 2.6 V, about 2 V to about 2.8 V, about 2.2 Vto about 2.4 V, about 2.2 V to about 2.6 V, about 2.2 V to about 2.8 V,about 2.4 V to about 2.6 V, about 2.4 V to about 2.8 V, or about 2.6 Vto about 2.8 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 2 A/g, of about 2,500 F/g to about 10,000F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of at least about2,500 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of at most about10,000 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 2 A/g, of about 2,500 F/g toabout 3,000 F/g, about 2,500 F/g to about 4,000 F/g, about 2,500 F/g toabout 5,000 F/g, about 2,500 F/g to about 6,000 F/g, about 2,500 F/g toabout 7,000 F/g, about 2,500 F/g to about 8,000 F/g, about 2,500 F/g toabout 9,000 F/g, about 2,500 F/g to about 10,000 F/g, about 3,000 F/g toabout 4,000 F/g, about 3,000 F/g to about 5,000 F/g, about 3,000 F/g toabout 6,000 F/g, about 3,000 F/g to about 7,000 F/g, about 3,000 F/g toabout 8,000 F/g, about 3,000 F/g to about 9,000 F/g, about 3,000 F/g toabout 10,000 F/g, about 4,000 F/g to about 5,000 F/g, about 4,000 F/g toabout 6,000 F/g, about 4,000 F/g to about 7,000 F/g, about 4,000 F/g toabout 8,000 F/g, about 4,000 F/g to about 9,000 F/g, about 4,000 F/g toabout 10,000 F/g, about 5,000 F/g to about 6,000 F/g, about 5,000 F/g toabout 7,000 F/g, about 5,000 F/g to about 8,000 F/g, about 5,000 F/g toabout 9,000 F/g, about 5,000 F/g to about 10,000 F/g, about 6,000 F/g toabout 7,000 F/g, about 6,000 F/g to about 8,000 F/g, about 6,000 F/g toabout 9,000 F/g, about 6,000 F/g to about 10,000 F/g, about 7,000 F/g toabout 8,000 F/g, about 7,000 F/g to about 9,000 F/g, about 7,000 F/g toabout 10,000 F/g, about 8,000 F/g to about 9,000 F/g, about 8,000 F/g toabout 10,000 F/g, or about 9,000 F/g to about 10,000 F/g.

In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the weight of the electrodes, of about 700Wh/kg to about 3,000 Wh/kg. In those embodiments, the supercapacitor hasa gravimetric energy density, as normalized by the weight of theelectrodes, of at least about 700 Wh/kg. In those embodiments, thesupercapacitor has a gravimetric energy density, as normalized by theweight of the electrodes, of at most about 3.00 Wh/kg. In thoseembodiments, the supercapacitor has a gravimetric energy density, asnormalized by the weight of the electrodes, of about 700 Wh/kg to about1,000 Wh/kg, about 700 Wh/kg to about 1,250 Wh/kg, about 700 Wh/kg toabout 1,500 Wh/kg, about 700 Wh/kg to about 1,750 Wh/kg, about 700 Wh/kgto about 2,000 Wh/kg, about 700 Wh/kg to about 2,250 Wh/kg, about 700Wh/kg to about 2,500 Wh/kg, about 700 Wh/kg to about 2,750 Wh/kg, about700 Wh/kg to about 3,000 Wh/kg, about 1,000 Wh/kg to about 1,250 Wh/kg,about 1,000 Wh/kg to about 1,500 Wh/kg, about 1,000 Wh/kg to about 1,750Wh/kg, about 1,000 Wh/kg to about 2,000 Wh/kg, about 1,000 Wh/kg toabout 2,250 Wh/kg, about 1,000 Wh/kg to about 2,500 Wh/kg, about 1,000Wh/kg to about 2,750 Wh/kg, about 1,000 Wh/kg to about 3,000 Wh/kg,about 1,250 Wh/kg to about 1,500 Wh/kg, about 1,250 Wh/kg to about 1,750Wh/kg, about 1,250 Wh/kg to about 2,000 Wh/kg, about 1,250 Wh/kg toabout 2,250 Wh/kg, about 1,250 Wh/kg to about 2,500 Wh/kg, about 1,250Wh/kg to about 2,750 Wh/kg, about 1,250 Wh/kg to about 3,000 Wh/kg,about 1,500 Wh/kg to about 1,750 Wh/kg, about 1,500 Wh/kg to about 2,000Wh/kg, about 1,500 Wh/kg to about 2,250 Wh/kg, about 1,500 Wh/kg toabout 2,500 Wh/kg, about 1,500 Wh/kg to about 2,750 Wh/kg, about 1,500Wh/kg to about 3,000 Wh/kg, about 1,750 Wh/kg to about 2,000 Wh/kg,about 1,750 Wh/kg to about 2,250 Wh/kg, about 1,750 Wh/kg to about 2,500Wh/kg, about 1,750 Wh/kg to about 2,750 Wh/kg, about 1,750 Wh/kg toabout 3,000 Wh/kg, about 2,000 Wh/kg to about 2,250 Wh/kg, about 2,000Wh/kg to about 2,500 Wh/kg, about 2,000 Wh/kg to about 2,750 Wh/kg,about 2,000 Wh/kg to about 3,000 Wh/kg, about 2,250 Wh/kg to about 2,500Wh/kg, about 2,250 Wh/kg to about 2,750 Wh/kg, about 2,250 Wh/kg toabout 3,000 Wh/kg, about 2,500 Wh/kg to about 2,750 Wh/kg, about 2,500Wh/kg to about 3,000 Wh/kg, or about 2,750 Wh/kg to about 3,000 Wh/kg.

In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the volume of the electrodes, of about 100Wh/L to about 2,000 Wh/L. In those embodiments, the supercapacitor has agravimetric energy density, as normalized by the volume of theelectrodes, of at least about 100 Wh/L. In those embodiments, thesupercapacitor has a gravimetric energy density, as normalized by thevolume of the electrodes, of at most about 2,000 Wh/L. In thoseembodiments, the supercapacitor has a gravimetric energy density, asnormalized by the volume of the electrodes, of about 500 Wh/L to about625 Wh/L, about 500 Wh/L to about 750 Wh/L, about 500 Wh/L to about 875Wh/L, about 500 Wh/L to about 100 Wh/L, about 500 Wh/L to about 1,125Wh/L, about 500 Wh/L to about 1,250 Wh/L, about 500 Wh/L to about 1,375Wh/L, about 500 Wh/L to about 1,500 Wh/L, about 500 Wh/L to about 1,750Wh/L, about 500 Wh/L to about 2,000 Wh/L, about 625 Wh/L to about 750Wh/L, about 625 Wh/L to about 875 Wh/L, about 625 Wh/L to about 100Wh/L, about 625 Wh/L to about 1,125 Wh/L, about 625 Wh/L to about 1,250Wh/L, about 625 Wh/L to about 1,375 Wh/L, about 625 Wh/L to about 1,500Wh/L, about 625 Wh/L to about 1,750 Wh/L, about 625 Wh/L to about 2,000Wh/L, about 750 Wh/L to about 875 Wh/L, about 750 Wh/L to about 100Wh/L, about 750 Wh/L to about 1,125 Wh/L, about 750 Wh/L to about 1,250Wh/L, about 750 Wh/L to about 1,375 Wh/L, about 750 Wh/L to about 1,500Wh/L, about 750 Wh/L to about 1,750 Wh/L, about 750 Wh/L to about 2,000Wh/L, about 875 Wh/L to about 100 Wh/L, about 875 Wh/L to about 1,125Wh/L, about 875 Wh/L to about 1,250 Wh/L, about 875 Wh/L to about 1,375Wh/L, about 875 Wh/L to about 1,500 Wh/L, about 875 Wh/L to about 1,750Wh/L, about 875 Wh/L to about 2,000 Wh/L, about 100 Wh/L to about 1,125Wh/L, about 100 Wh/L to about 1,250 Wh/L, about 100 Wh/L to about 1,375Wh/L, about 100 Wh/L to about 1,500 Wh/L, about 100 Wh/L to about 1,750Wh/L, about 100 Wh/L to about 2,000 Wh/L, about 1,125 Wh/L to about1,250 Wh/L, about 1,125 Wh/L to about 1,375 Wh/L, about 1,125 Wh/L toabout 1,500 Wh/L, about 1,125 Wh/L to about 1,750 Wh/L, about 1,125 Wh/Lto about 2,000 Wh/L, about 1,250 Wh/L to about 1,375 Wh/L, about 1,250Wh/L to about 1,500 Wh/L, about 1,250 Wh/L to about 1,750 Wh/L, about1,250 Wh/L to about 2,000 Wh/L, about 1,375 Wh/L to about 1,500 Wh/L,about 1,375 Wh/L to about 1,750 Wh/L, about 1,375 Wh/L to about 2,000Wh/L, about 1,500 Wh/L to about 1,750 Wh/L, about 1,500 Wh/L to about2,000 Wh/L, or about 1,750 Wh/L to about 2,000 Wh/L.

In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the volume of the electrodes and the redoxelectrolyte, of about 100 Wh/kg to about 2,000 Wh/kg. In thoseembodiments, the supercapacitor has a gravimetric energy density, asnormalized by the volume of the electrodes and the redox electrolyte, ofat least about 100 Wh/kg. In those embodiments, the supercapacitor has agravimetric energy density, as normalized by the volume of theelectrodes and the redox electrolyte, of at most about 2,000 Wh/kg. Inthose embodiments, the supercapacitor has a gravimetric energy density,as normalized by the volume of the electrodes and the redox electrolyte,of about 500 Wh/kg to about 625 Wh/kg, about 500 Wh/kg to about 750Wh/kg, about 500 Wh/kg to about 875 Wh/kg, about 500 Wh/kg to about 100Wh/kg, about 500 Wh/kg to about 1,125 Wh/kg, about 500 Wh/kg to about1,250 Wh/kg, about 500 Wh/kg to about 1,375 Wh/kg, about 500 Wh/kg toabout 1,500 Wh/kg, about 500 Wh/kg to about 1,750 Wh/kg, about 500 Wh/kgto about 2,000 Wh/kg, about 625 Wh/kg to about 750 Wh/kg, about 625Wh/kg to about 875 Wh/kg, about 625 Wh/kg to about 100 Wh/kg, about 625Wh/kg to about 1,125 Wh/kg, about 625 Wh/kg to about 1,250 Wh/kg, about625 Wh/kg to about 1,375 Wh/kg, about 625 Wh/kg to about 1,500 Wh/kg,about 625 Wh/kg to about 1,750 Wh/kg, about 625 Wh/kg to about 2,000Wh/kg, about 750 Wh/kg to about 875 Wh/kg, about 750 Wh/kg to about 100Wh/kg, about 750 Wh/kg to about 1,125 Wh/kg, about 750 Wh/kg to about1,250 Wh/kg, about 750 Wh/kg to about 1,375 Wh/kg, about 750 Wh/kg toabout 1,500 Wh/kg, about 750 Wh/kg to about 1,750 Wh/kg, about 750 Wh/kgto about 2,000 Wh/kg, about 875 Wh/kg to about 100 Wh/kg, about 875Wh/kg to about 1,125 Wh/kg, about 875 Wh/kg to about 1,250 Wh/kg, about875 Wh/kg to about 1,375 Wh/kg, about 875 Wh/kg to about 1,500 Wh/kg,about 875 Wh/kg to about 1,750 Wh/kg, about 875 Wh/kg to about 2,000Wh/kg, about 100 Wh/kg to about 1,125 Wh/kg, about 100 Wh/kg to about1,250 Wh/kg, about 100 Wh/kg to about 1,375 Wh/kg, about 100 Wh/kg toabout 1,500 Wh/kg, about 100 Wh/kg to about 1,750 Wh/kg, about 100 Wh/kgto about 2,000 Wh/kg, about 1,125 Wh/kg to about 1,250 Wh/kg, about1,125 Wh/kg to about 1,375 Wh/kg, about 1,125 Wh/kg to about 1,500Wh/kg, about 1,125 Wh/kg to about 1,750 Wh/kg, about 1,125 Wh/kg toabout 2,000 Wh/kg, about 1,250 Wh/kg to about 1,375 Wh/kg, about 1,250Wh/kg to about 1,500 Wh/kg, about 1,250 Wh/kg to about 1,750 Wh/kg,about 1,250 Wh/kg to about 2,000 Wh/kg, about 1,375 Wh/kg to about 1,500Wh/kg, about 1,375 Wh/kg to about 1,750 Wh/kg, about 1,375 Wh/kg toabout 2,000 Wh/kg, about 1,500 Wh/kg to about 1,750 Wh/kg, about 1,500Wh/kg to about 2,000 Wh/kg, or about 1,750 Wh/kg to about 2,000 Wh/kg.

In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the volume of the electrodes and the redoxelectrolyte, of about 100 Wh/L to about 1,800 Wh/L. In thoseembodiments, the supercapacitor has a gravimetric energy density, asnormalized by the volume of the electrodes and the redox electrolyte, ofat least about 100 Wh/L. In those embodiments, the supercapacitor has agravimetric energy density, as normalized by the volume of theelectrodes and the redox electrolyte, of at most about 1,800 Wh/L. Inthose embodiments, the supercapacitor has a gravimetric energy density,as normalized by the volume of the electrodes and the redox electrolyte,of about 400 Wh/L to about 600 Wh/L, about 400 Wh/L to about 800 Wh/L,about 400 Wh/L to about 100 Wh/L, about 400 Wh/L to about 1,200 Wh/L,about 400 Wh/L to about 1,400 Wh/L, about 400 Wh/L to about 1,600 Wh/L,about 400 Wh/L to about 1,800 Wh/L, about 600 Wh/L to about 800 Wh/L,about 600 Wh/L to about 100 Wh/L, about 600 Wh/L to about 1,200 Wh/L,about 600 Wh/L to about 1,400 Wh/L, about 600 Wh/L to about 1,600 Wh/L,about 600 Wh/L to about 1,800 Wh/L, about 800 Wh/L to about 100 Wh/L,about 800 Wh/L to about 1,200 Wh/L, about 800 Wh/L to about 1,400 Wh/L,about 800 Wh/L to about 1,600 Wh/L, about 800 Wh/L to about 1,800 Wh/L,about 100 Wh/L to about 1,200 Wh/L, about 100 Wh/L to about 1,400 Wh/L,about 100 Wh/L to about 1,600 Wh/L, about 100 Wh/L to about 1,800 Wh/L,about 1,200 Wh/L to about 1,400 Wh/L, about 1,200 Wh/L to about 1,600Wh/L, about 1,200 Wh/L to about 1,800 Wh/L, about 1,400 Wh/L to about1,600 Wh/L, about 1,400 Wh/L to about 1,800 Wh/L, or about 1,600 Wh/L toabout 1,800 Wh/L.

In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the mass and volume of the electrodes, theredox electrolyte and the carbon cloth, of about 30 Wh/kg to about 120Wh/kg. In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the mass and volume of the electrodes, theredox electrolyte and the carbon cloth, of at least about 30 Wh/kg. Inthose embodiments, the supercapacitor has a gravimetric energy density,as normalized by the mass and volume of the electrodes, the redoxelectrolyte, and the carbon cloth, of at most about 120 Wh/kg. In thoseembodiments, the supercapacitor has a gravimetric energy density, asnormalized by the mass and volume of the electrodes, the redoxelectrolyte and the carbon cloth, of about 30 Wh/kg to about 40 Wh/kg,about 30 Wh/kg to about 50 Wh/kg, about 30 Wh/kg to about 60 Wh/kg,about 30 Wh/kg to about 70 Wh/kg, about 30 Wh/kg to about 80 Wh/kg,about 30 Wh/kg to about 90 Wh/kg, about 30 Wh/kg to about 100 Wh/kg,about 30 Wh/kg to about 120 Wh/kg, about 40 Wh/kg to about 50 Wh/kg,about 40 Wh/kg to about 60 Wh/kg, about 40 Wh/kg to about 70 Wh/kg,about 40 Wh/kg to about 80 Wh/kg, about 40 Wh/kg to about 90 Wh/kg,about 40 Wh/kg to about 100 Wh/kg, about 40 Wh/kg to about 120 Wh/kg,about 50 Wh/kg to about 60 Wh/kg, about 50 Wh/kg to about 70 Wh/kg,about 50 Wh/kg to about 80 Wh/kg, about 50 Wh/kg to about 90 Wh/kg,about 50 Wh/kg to about 100 Wh/kg, about 50 Wh/kg to about 120 Wh/kg,about 60 Wh/kg to about 70 Wh/kg, about 60 Wh/kg to about 80 Wh/kg,about 60 Wh/kg to about 90 Wh/kg, about 60 Wh/kg to about 100 Wh/kg,about 60 Wh/kg to about 120 Wh/kg, about 70 Wh/kg to about 80 Wh/kg,about 70 Wh/kg to about 90 Wh/kg, about 70 Wh/kg to about 100 Wh/kg,about 70 Wh/kg to about 120 Wh/kg, about 80 Wh/kg to about 90 Wh/kg,about 80 Wh/kg to about 100 Wh/kg, about 80 Wh/kg to about 120 Wh/kg,about 90 Wh/kg to about 100 Wh/kg, about 90 Wh/kg to about 120 Wh/kg, orabout 100 Wh/kg to about 120 Wh/kg.

In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the mass and volume of the electrodes, theredox electrolyte and the carbon cloth, of about 40 Wh/L to about 180Wh/L. In those embodiments, the supercapacitor has a gravimetric energydensity, as normalized by the mass and volume of the electrodes, theredox electrolyte and the carbon cloth, of at least about 40 Wh/L. Inthose embodiments, the supercapacitor has a gravimetric energy density,as normalized by the mass and volume of the electrodes, the redoxelectrolyte and the carbon cloth, of at most about 180 Wh/L. In thoseembodiments, the supercapacitor has a gravimetric energy density, asnormalized by the mass and volume of the electrodes, the redoxelectrolyte and the carbon cloth, of about 40 Wh/L to about 50 Wh/L,about 40 Wh/L to about 60 Wh/L, about 40 Wh/L to about 70 Wh/L, about 40Wh/L to about 80 Wh/L, about 40 Wh/L to about 90 Wh/L, about 40 Wh/L toabout 100 Wh/L, about 40 Wh/L to about 120 Wh/L, about 40 Wh/L to about140 Wh/L, about 40 Wh/L to about 160 Wh/L, about 40 Wh/L to about 180Wh/L, about 50 Wh/L to about 60 Wh/L, about 50 Wh/L to about 70 Wh/L,about 50 Wh/L to about 80 Wh/L, about 50 Wh/L to about 90 Wh/L, about 50Wh/L to about 100 Wh/L, about 50 Wh/L to about 120 Wh/L, about 50 Wh/Lto about 140 Wh/L, about 50 Wh/L to about 160 Wh/L, about 50 Wh/L toabout 180 Wh/L, about 60 Wh/L to about 70 Wh/L, about 60 Wh/L to about80 Wh/L, about 60 Wh/L to about 90 Wh/L, about 60 Wh/L to about 100Wh/L, about 60 Wh/L to about 120 Wh/L, about 60 Wh/L to about 140 Wh/L,about 60 Wh/L to about 160 Wh/L, about 60 Wh/L to about 180 Wh/L, about70 Wh/L to about 80 Wh/L, about 70 Wh/L to about 90 Wh/L, about 70 Wh/Lto about 100 Wh/L, about 70 Wh/L to about 120 Wh/L, about 70 Wh/L toabout 140 Wh/L, about 70 Wh/L to about 160 Wh/L, about 70 Wh/L to about180 Wh/L, about 80 Wh/L to about 90 Wh/L, about 80 Wh/L to about 100Wh/L, about 80 Wh/L to about 120 Wh/L, about 80 Wh/L to about 140 Wh/L,about 80 Wh/L to about 160 Wh/L, about 80 Wh/L to about 180 Wh/L, about90 Wh/L to about 100 Wh/L, about 90 Wh/L to about 120 Wh/L, about 90Wh/L to about 140 Wh/L, about 90 Wh/L to about 160 Wh/L, about 90 Wh/Lto about 180 Wh/L, about 100 Wh/L to about 120 Wh/L, about 100 Wh/L toabout 140 Wh/L, about 100 Wh/L to about 160 Wh/L, about 100 Wh/L toabout 180 Wh/L, about 120 Wh/L to about 140 Wh/L, about 120 Wh/L toabout 160 Wh/L, about 120 Wh/L to about 180 Wh/L, about 140 Wh/L toabout 160 Wh/L, about 140 Wh/L to about 180 Wh/L, or about 160 Wh/L toabout 180 Wh/L.

A fourth aspect disclosed herein is a supercapacitor comprising threeelectrodes, wherein each electrode comprises an activated carbonelectrode, a current collector, and an electrolyte. In some embodiments,the current collector is metallic. In some embodiments, the currentcollector is ferritic. In some embodiments, the current collectorcomprises stainless steel, crucible steel, carbon steel, spring steel,alloy steel, maraging steel, weathering steel, tool steel, or anycombination thereof.

In some embodiments, the electrolyte is disposed between the electrodes.In some embodiments, the electrolyte comprises an acid. In someembodiments, the electrolyte comprises a solvent. In some embodiments,the electrolyte comprises an acid and a solvent. In some embodiments,the acid is a strong acid. In some embodiments, the strong acidcomprises perchloric acid, hydroiodic acid, hydrobromic acid,hydrochloric acid, sulfuric acid, p-toluenesulfonic acid methanesulfonicacid, or any combination thereof. In some embodiments, the solventcomprises tetrahydrofuran, ethyl acetate, dimethylformamide,acetonitrile, acetone, dimethyl sulfoxide, nitromethane, propylenecarbonate, ethanol, formic acid, n-butanol, methanol, acetic acid,water, or any combination thereof.

In some embodiments, the electrolyte is a gel electrolyte, wherein thegel electrolyte comprises a quinone. In those embodiments, theconcentration of the quinone is about 0.25 millimolar to about 1millimolar. In those embodiments, the concentration of the quinone is atleast about 0.25 millimolar. In those embodiments, the concentration ofthe quinone is at most about 1 millimolar. In those embodiments, theconcentration of the quinone is about 0.25 millimolar to about 0.375millimolar, about 0.25 millimolar to about 0.5 millimolar, about 0.25millimolar to about 0.625 millimolar, about 0.25 millimolar to about0.75 millimolar, about 0.25 millimolar to about 1 millimolar, about0.375 millimolar to about 0.5 millimolar, about 0.375 millimolar toabout 0.625 millimolar, about 0.375 millimolar to about 0.75 millimolar,about 0.375 millimolar to about 1 millimolar, about 0.5 millimolar toabout 0.625 millimolar, about 0.5 millimolar to about 0.75 millimolar,about 0.5 millimolar to about 1 millimolar, about 0.625 millimolar toabout 0.75 millimolar, about 0.625 millimolar to about 1 millimolar, orabout 0.75 millimolar to about 1 millimolar.

In those embodiments, the supercapacitor has a working potential ofabout 0.2 V to about 1.2 V. In those embodiments, the supercapacitor hasa working potential of at least about 0.2 V. In those embodiments, thesupercapacitor has a working potential of at most about 1.2 V. In thoseembodiments, the supercapacitor has a working potential of about 0.2 Vto about 0.3 V, about 0.2 V to about 0.4 V, about 0.2 V to about 0.6 V,about 0.2 V to about 0.8 V, about 0.2 V to about 1 V, about 0.2 V toabout 1.2 V, about 0.3 V to about 0.4 V, about 0.3 V to about 0.6 V,about 0.3 V to about 0.8 V, about 0.3 V to about 1 V, about 0.3 V toabout 1.2 V, about 0.4 V to about 0.6 V, about 0.4 V to about 0.8 V,about 0.4 V to about 1 V, about 0.4 V to about 1.2 V, about 0.6 V toabout 0.8 V, about 0.6 V to about 1 V, about 0.6 V to about 1.2 V, about0.8 V to about 1 V, about 0.8 V to about 1.2 V, or about 1 V to about1.2 V.

In those embodiments, the supercapacitor has a gravimetric capacitance,in a current density of about 10 A/g, of about 1,000 F/g to about 8,000F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 10 A/g, of at least about1,000 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 10 A/g, of at most about8,000 F/g. In those embodiments, the supercapacitor has a gravimetriccapacitance, in a current density of about 10 A/g, of about 7,000 F/g toabout 8,000 F/g, about 7,000 F/g to about 1,000 F/g, about 7,000 F/g toabout 1,250 F/g, about 7,000 F/g to about 1,500 F/g, about 7,000 F/g toabout 2,000 F/g, about 7,000 F/g to about 2,250 F/g, about 7,000 F/g toabout 2,500 F/g, about 7,000 F/g to about 2,800 F/g, about 8,000 F/g toabout 1,000 F/g, about 8,000 F/g to about 1,250 F/g, about 8,000 F/g toabout 1,500 F/g, about 8,000 F/g to about 2,000 F/g, about 8,000 F/g toabout 2,250 F/g, about 8,000 F/g to about 2,500 F/g, about 8,000 F/g toabout 2,800 F/g, about 1,000 F/g to about 1,250 F/g, about 1,000 F/g toabout 1,500 F/g, about 1,000 F/g to about 2,000 F/g, about 1,000 F/g toabout 2,250 F/g, about 1,000 F/g to about 2,500 F/g, about 1,000 F/g toabout 2,800 F/g, about 1,250 F/g to about 1,500 F/g, about 1,250 F/g toabout 2,000 F/g, about 1,250 F/g to about 2,250 F/g, about 1,250 F/g toabout 2,500 F/g, about 1,250 F/g to about 2,800 F/g, about 1,500 F/g toabout 2,000 F/g, about 1,500 F/g to about 2,250 F/g, about 1,500 F/g toabout 2,500 F/g, about 1,500 F/g to about 2,800 F/g, about 2,000 F/g toabout 2,250 F/g, about 2,000 F/g to about 2,500 F/g, about 2,000 F/g toabout 2,800 F/g, about 2,250 F/g to about 2,500 F/g, about 2,250 F/g toabout 2,800 F/g, or about 2,500 F/g to about 2,800 F/g.

A fifth aspect provided herein is a method of fabricating afunctionalized carbon electrode comprising the steps of functionalizinga carbon substrate, preparing the functionalized carbon substrate,formulating a polymerization fluid, and synthesizing a nanotube on thefunctionalized carbon substrate.

In some embodiments, the functionalized carbon electrode is apolyaniline functionalized carbon electrode. In some embodiments, thenanotube is a polyaniline nanotube.

In some embodiments the step of functionalizing a carbon substratecomprises forming an functionalization solution, heating thefunctionalization solution, cooling the functionalization solution,displacing a piece of carbon substrate into the functionalizationsolution, and rinsing a piece of functionalized carbon substrate. Insome embodiments the substrate is rinsed in water.

In some embodiments, the functionalization solution comprises a strongacid comprising perchloric acid, hydroiodic acid, hydrobromic acid,hydrochloric acid, sulfuric acid, p-toluenesulfonic acid,methanesulfonic acid, and nitric acid, chloric acid, or any combinationthereof.

In some embodiments, the functionalization solution comprises a firststrong acid and a second strong acid wherein the first strong acidcomprises perchloric acid, hydroiodic acid, hydrobromic acid,hydrochloric acid, sulfuric acid, p-toluenesulfonic acid,methanesulfonic acid, nitric acid chloric acid, or any combinationthereof. In some embodiments, the second strong acid comprisesperchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid,sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, nitric acidchloric acid, or any combination thereof.

In some embodiments, the functionalization solution comprises a volumepercentage of the first strong acid of about 15% to about 60%. In someembodiments, the functionalization solution comprises a volumepercentage of the first strong acid of at least about 15%. In someembodiments, the functionalization solution comprises a volumepercentage of the first strong acid of at most about 60%. In someembodiments, the functionalization solution comprises a volumepercentage of the first strong acid of about 15% to about 20%, about 15%to about 25%, about 15% to about 30%, about 15% to about 35%, about 15%to about 40%, about 15% to about 45%, about 15% to about 50%, about 15%to about 55%, about 15% to about 60%, about 20% to about 25%, about 20%to about 30%, about 20% to about 35%, about 20% to about 40%, about 20%to about 45%, about 20% to about 50%, about 20% to about 55%, about 20%to about 60%, about 25% to about 30%, about 25% to about 35%, about 25%to about 40%, about 25% to about 45%, about 25% to about 50%, about 25%to about 55%, about 25% to about 60%, about 30% to about 35%, about 30%to about 40%, about 30% to about 45%, about 30% to about 50%, about 30%to about 55%, about 30% to about 60%, about 35% to about 40%, about 35%to about 45%, about 35% to about 50%, about 35% to about 55%, about 35%to about 60%, about 40% to about 45%, about 40% to about 50%, about 40%to about 55%, about 40% to about 60%, about 45% to about 50%, about 45%to about 55%, about 45% to about 60%, about 50% to about 55%, about 50%to about 60%, or about 55% to about 60%.

In some embodiments, the functionalization solution is heated to atemperature of about 30° C. to about 120° C. In some embodiments, thefunctionalization solution is heated to a temperature of at least about30° C. In some embodiments, the functionalization solution is heated toa temperature of at most about 120° C. In some embodiments, thefunctionalization solution is heated to a temperature of about 30° C. toabout 40° C., about 30° C. to about 50° C., about 30° C. to about 60°C., about 30° C. to about 70° C., about 30° C. to about 80° C., about30° C. to about 90° C., about 30° C. to about 100° C., about 30° C. toabout 110° C., about 30° C. to about 120° C., about 40° C. to about 50°C., about 40° C. to about 60° C., about 40° C. to about 70° C., about40° C. to about 80° C., about 40° C. to about 90° C., about 40° C. toabout 100° C., about 40° C. to about 110° C., about 40° C. to about 120°C., about 50° C. to about 60° C., about 50° C. to about 70° C., about50° C. to about 80° C., about 50° C. to about 90° C., about 50° C. toabout 100° C., about 50° C. to about 110° C., about 50° C. to about 120°C., about 60° C. to about 70° C., about 60° C. to about 80° C., about60° C. to about 90° C., about 60° C. to about 100° C., about 60° C. toabout 110° C., about 60° C. to about 120° C., about 70° C. to about 80°C., about 70° C. to about 90° C., about 70° C. to about 100° C., about70° C. to about 110° C., about 70° C. to about 120° C., about 80° C. toabout 90° C., about 80° C. to about 100° C., about 80° C. to about 110°C., about 80° C. to about 120° C., about 90° C. to about 100° C., about90° C. to about 110° C., about 90° C. to about 120° C., about 100° C. toabout 110° C., about 100° C. to about 120° C., or about 110° C. to about120° C.

In some embodiments, the functionalization solution is heated for aperiod of about 60 minutes to about 240 minutes. In some embodiments,the functionalization solution is heated for a period of at least about60 minutes. In some embodiments, the functionalization solution isheated for a period of at most about 240 minutes. In some embodiments,the functionalization solution is heated for a period of about 60minutes to about 80 minutes, about 60 minutes to about 100 minutes,about 60 minutes to about 120 minutes, about 60 minutes to about 140minutes, about 60 minutes to about 160 minutes, about 60 minutes toabout 180 minutes, about 60 minutes to about 200 minutes, about 60minutes to about 220 minutes, about 60 minutes to about 240 minutes,about 80 minutes to about 100 minutes, about 80 minutes to about 120minutes, about 80 minutes to about 140 minutes, about 80 minutes toabout 160 minutes, about 80 minutes to about 180 minutes, about 80minutes to about 200 minutes, about 80 minutes to about 220 minutes,about 80 minutes to about 240 minutes, about 100 minutes to about 120minutes, about 100 minutes to about 140 minutes, about 100 minutes toabout 160 minutes, about 100 minutes to about 180 minutes, about 100minutes to about 200 minutes, about 100 minutes to about 220 minutes,about 100 minutes to about 240 minutes, about 120 minutes to about 140minutes, about 120 minutes to about 160 minutes, about 120 minutes toabout 180 minutes, about 120 minutes to about 200 minutes, about 120minutes to about 220 minutes, about 120 minutes to about 240 minutes,about 140 minutes to about 160 minutes, about 140 minutes to about 180minutes, about 140 minutes to about 200 minutes, about 140 minutes toabout 220 minutes, about 140 minutes to about 240 minutes, about 160minutes to about 180 minutes, about 160 minutes to about 200 minutes,about 160 minutes to about 220 minutes, about 160 minutes to about 240minutes, about 180 minutes to about 200 minutes, about 180 minutes toabout 220 minutes, about 180 minutes to about 240 minutes, about 200minutes to about 220 minutes, about 200 minutes to about 240 minutes, orabout 220 minutes to about 240 minutes.

In some embodiments, the functionalization solution is cooled to roomtemperature. In some embodiments, the water is deionized.

In some embodiments, the water is heated to a temperature of about 5° C.to about 40° C. In some embodiments, the water is heated to atemperature of at least about 5° C. In some embodiments, the water isheated to a temperature of at most about 40° C. In some embodiments, thewater is heated to a temperature of about 5° C. to about 10° C., about5° C. to about 15° C., about 5° C. to about 20° C., about 5° C. to about25° C., about 5° C. to about 30° C., about 5° C. to about 35° C., about5° C. to about 40° C., about 10° C. to about 15° C., about 10° C. toabout 20° C., about 10° C. to about 25° C., about 10° C. to about 30°C., about 10° C. to about 35° C., about 10° C. to about 40° C., about15° C. to about 20° C., about 15° C. to about 25° C., about 15° C. toabout 30° C., about 15° C. to about 35° C., about 15° C. to about 40°C., about 20° C. to about 25° C., about 20° C. to about 30° C., about20° C. to about 35° C., about 20° C. to about 40° C., about 25° C. toabout 30° C., about 25° C. to about 35° C., about 25° C. to about 40°C., about 30° C. to about 35° C., about 30° C. to about 40° C., or about35° C. to about 40° C.

In some embodiments, the volume of water is about 0.5 liters (L) toabout 2 L. In some embodiments, the volume of water is at least about0.5 L. In some embodiments, the volume of water is at most about 2 L. Insome embodiments, the volume of water is about 0.5 L to about 0.625 L,about 0.5 L to about 0.75 L, about 0.5 L to about 0.875 L, about 0.5 Lto about 1 L, about 0.5 L to about 1.25 L, about 0.5 L to about 1.5 L,about 0.5 L to about 1.75 L, about 0.5 L to about 2 L, about 0.625 L toabout 0.75 L, about 0.625 L to about 0.875 L, about 0.625 L to about 1L, about 0.625 L to about 1.25 L, about 0.625 L to about 1.5 L, about0.625 L to about 1.75 L, about 0.625 L to about 2 L, about 0.75 L toabout 0.875 L, about 0.75 L to about 1 L, about 0.75 L to about 1.25 L,about 0.75 L to about 1.5 L, about 0.75 L to about 1.75 L, about 0.75 Lto about 2 L, about 0.875 L to about 1 L, about 0.875 L to about 1.25 L,about 0.875 L to about 1.5 L, about 0.875 L to about 1.75 L, about 0.875L to about 2 L, about 1 L to about 1.25 L, about 1 L to about 1.5 L,about 1 L to about 1.75 L, about 1 L to about 2 L, about 1.25 L to about1.5 L, about 1.25 L to about 1.75 L, about 1.25 L to about 2 L, about1.5 L to about 1.75 L, about 1.5 L to about 2 L, or about 1.75 L toabout 2 L.

In some embodiments, the carbon substrate is comprised of a carboncloth, carbon fiber, amorphous carbon, glassy carbon, carbon nanofoam,carbon aerogel, or any combination thereof.

In some embodiments, the functionalized carbon substrate is annealedafter functionalization.

In some embodiments, the annealing temperature is about 100° C. to about400° C. In some embodiments, the annealing temperature is at least about100° C. In some embodiments, the annealing temperature is at most about400° C. In some embodiments, the annealing temperature is about 100° C.to about 150° C., about 100° C. to about 200° C., about 100° C. to about250° C., about 100° C. to about 300° C., about 100° C. to about 350° C.,about 100° C. to about 400° C., about 150° C. to about 200° C., about150° C. to about 250° C., about 150° C. to about 300° C., about 150° C.to about 350° C., about 150° C. to about 400° C., about 200° C. to about250° C., about 200° C. to about 300° C., about 200° C. to about 350° C.,about 200° C. to about 400° C., about 250° C. to about 300° C., about250° C. to about 350° C., about 250° C. to about 400° C., about 300° C.to about 350° C., about 300° C. to about 400° C., or about 350° C. toabout 400° C.

In some embodiments, the functionalized carbon substrate is annealed fora period of about 0.5 hours to about 14 hours. In some embodiments, thefunctionalized carbon substrate is annealed for a period of at leastabout 0.5 hours. In some embodiments, the functionalized carbonsubstrate is annealed for a period of at most about 14 hours. In someembodiments, the functionalized carbon substrate is annealed for aperiod of about 0.5 hours to about 1 hour, about 0.5 hours to about 2hours, about 0.5 hours to about 5 hours, about 0.5 hours to about 7hours, about 0.5 hours to about 9 hours, about 0.5 hours to about 11hours, about 0.5 hours to about 14 hours, about 1 hour to about 2 hours,about 1 hour to about 5 hours, about 1 hour to about 7 hours, about 1hour to about 9 hours, about 1 hour to about 11 hours, about 1 hour toabout 14 hours, about 2 hours to about 5 hours, about 2 hours to about 7hours, about 2 hours to about 9 hours, about 2 hours to about 11 hours,about 2 hours to about 14 hours, about 5 hours to about 7 hours, about 5hours to about 9 hours, about 5 hours to about 11 hours, about 5 hoursto about 14 hours, about 7 hours to about 9 hours, about 7 hours toabout 11 hours, about 7 hours to about 14 hours, about 9 hours to about11 hours, about 9 hours to about 14 hours, or about 11 hours to about 14hours.

In some embodiments, the step of preparing the functionalized carbonsubstrate comprises cutting a piece of functionalized carbon substrate,submerging the piece of functionalized carbon substrate in a solventsolution, sonicating the piece functionalized carbon substrate in thesolvent solution, and drying the piece of functionalized carbonsubstrate.

In some embodiments, the functionalized carbon substrate has a geometricarea of about 0.1 square centimeters (cm²) to about 0.5 cm². In someembodiments, the functionalized carbon substrate has a geometric area ofat least about 0.1 cm². In some embodiments, the functionalized carbonsubstrate has a geometric area of at most about 0.5 cm². In someembodiments, the functionalized carbon substrate has a geometric area ofabout 0.1 cm² to about 0.2 cm², about 0.1 cm² to about 0.3 cm², about0.1 cm² to about 0.4 cm², about 0.1 cm² to about 0.5 cm², about 0.2 cm²to about 0.3 cm², about 0.2 cm² to about 0.4 cm², about 0.2 cm² to about0.5 cm², about 0.3 cm² to about 0.4 cm², about 0.3 cm² to about 0.5 cm²,or about 0.4 cm² to about 0.5 cm².

In some embodiments, the solvent solution comprises tetrahydrofuran,ethyl acetate, dimethylformamide, acetonitrile, acetone, dimethylsulfoxide, nitromethane, propylene carbonate, ethanol, formic acid,n-butanol, methanol, acetic acid, water, or any combination thereof. Insome embodiments, the solvent solution comprises a first solvent and asecond solvent. In some embodiments, the first solvent solutioncomprises tetrahydrofuran, ethyl acetate, dimethylformamide,acetonitrile, acetone, dimethyl sulfoxide, nitromethane, propylenecarbonate, ethanol, formic acid, n-butanol, methanol, acetic acid,water, or any combination thereof. In some embodiments, the secondsolvent solution comprises tetrahydrofuran, ethyl acetate,dimethylformamide, acetonitrile, acetone, dimethyl sulfoxide,nitromethane, propylene carbonate, ethanol, formic acid, n-butanol,methanol, acetic acid, water, or any combination thereof.

In some embodiments, the first solvent comprises a volume percentage ofthe solvent solution of about 25% to about 95%. In some embodiments, thefirst solvent comprises a volume percentage of the solvent solution ofat least about 25%. In some embodiments, the first solvent comprises avolume percentage of the solvent solution of at most about 95%. In someembodiments, the first solvent comprises a volume percentage of thesolvent solution of about 25% to about 35%, about 25% to about 45%,about 25% to about 55%, about 25% to about 65%, about 25% to about 75%,about 25% to about 85%, about 25% to about 95%, about 35% to about 45%,about 35% to about 55%, about 35% to about 65%, about 35% to about 75%,about 35% to about 85%, about 35% to about 95%, about 45% to about 55%,about 45% to about 65%, about 45% to about 75%, about 45% to about 85%,about 45% to about 95%, about 55% to about 65%, about 55% to about 75%,about 55% to about 85%, about 55% to about 95%, about 65% to about 75%,about 65% to about 85%, about 65% to about 95%, about 75% to about 85%,about 75% to about 95%, or about 85% to about 95%.

In some embodiments, the period of sonication is about 30 minutes toabout 60 minutes. In some embodiments, the period of sonication is atleast about 30 minutes. In some embodiments, the period of sonication isat most about 60 minutes. In some embodiments, the period of sonicationis about 30 minutes to about 35 minutes, about 30 minutes to about 40minutes, about 30 minutes to about 45 minutes, about 30 minutes to about50 minutes, about 30 minutes to about 55 minutes, about 30 minutes toabout 60 minutes, about 35 minutes to about 40 minutes, about 35 minutesto about 45 minutes, about 35 minutes to about 50 minutes, about 35minutes to about 55 minutes, about 35 minutes to about 60 minutes, about40 minutes to about 45 minutes, about 40 minutes to about 50 minutes,about 40 minutes to about 55 minutes, about 40 minutes to about 60minutes, about 45 minutes to about 50 minutes, about 45 minutes to about55 minutes, about 45 minutes to about 60 minutes, about 50 minutes toabout 55 minutes, about 50 minutes to about 60 minutes, or about 55minutes to about 60 minutes.

In some embodiments, the drying occurs at a temperature of about 30° C.to about 120° C.

In some embodiments, the drying occurs at a temperature of at leastabout 30° C. In some embodiments, the drying occurs at a temperature ofat most about 120° C. In some embodiments, the drying occurs at atemperature of about 30° C. to about 40° C., about 30° C. to about 50°C., about 30° C. to about 60° C., about 30° C. to about 70° C., about30° C. to about 80° C., about 30° C. to about 90° C., about 30° C. toabout 100° C., about 30° C. to about 110° C., about 30° C. to about 120°C., about 40° C. to about 50° C., about 40° C. to about 60° C., about40° C. to about 70° C., about 40° C. to about 80° C., about 40° C. toabout 90° C., about 40° C. to about 100° C., about 40° C. to about 110°C., about 40° C. to about 120° C., about 50° C. to about 60° C., about50° C. to about 70° C., about 50° C. to about 80° C., about 50° C. toabout 90° C., about 50° C. to about 100° C., about 50° C. to about 110°C., about 50° C. to about 120° C., about 60° C. to about 70° C., about60° C. to about 80° C., about 60° C. to about 90° C., about 60° C. toabout 100° C., about 60° C. to about 110° C., about 60° C. to about 120°C., about 70° C. to about 80° C., about 70° C. to about 90° C., about70° C. to about 100° C., about 70° C. to about 110° C., about 70° C. toabout 120° C., about 80° C. to about 90° C., about 80° C. to about 100°C., about 80° C. to about 110° C., about 80° C. to about 120° C., about90° C. to about 100° C., about 90° C. to about 110° C., about 90° C. toabout 120° C., about 100° C. to about 110° C., about 100° C. to about120° C., or about 110° C. to about 120° C.

In some embodiments, the drying occurs over a period of time of about 3hours to about 12 hours. In some embodiments, the drying occurs over aperiod of time of at least about 3 hours. In some embodiments, thedrying occurs over a period of time of at most about 12 hours. In someembodiments, the drying occurs over a period of time of about 3 hours toabout 4 hours, about 3 hours to about 5 hours, about 3 hours to about 6hours, about 3 hours to about 7 hours, about 3 hours to about 8 hours,about 3 hours to about 9 hours, about 3 hours to about 10 hours, about 3hours to about 11 hours, about 3 hours to about 12 hours, about 4 hoursto about 5 hours, about 4 hours to about 6 hours, about 4 hours to about7 hours, about 4 hours to about 8 hours, about 4 hours to about 9 hours,about 4 hours to about 10 hours, about 4 hours to about 11 hours, about4 hours to about 12 hours, about 5 hours to about 6 hours, about 5 hoursto about 7 hours, about 5 hours to about 8 hours, about 5 hours to about9 hours, about 5 hours to about 10 hours, about 5 hours to about 11hours, about 5 hours to about 12 hours, about 6 hours to about 7 hours,about 6 hours to about 8 hours, about 6 hours to about 9 hours, about 6hours to about 10 hours, about 6 hours to about 11 hours, about 6 hoursto about 12 hours, about 7 hours to about 8 hours, about 7 hours toabout 9 hours, about 7 hours to about 10 hours, about 7 hours to about11 hours, about 7 hours to about 12 hours, about 8 hours to about 9hours, about 8 hours to about 10 hours, about 8 hours to about 11 hours,about 8 hours to about 12 hours, about 9 hours to about 10 hours, about9 hours to about 11 hours, about 9 hours to about 12 hours, about 10hours to about 11 hours, about 10 hours to about 12 hours, or about 11hours to about 12 hours.

In some embodiments the step of formulating a polymerization fluidcomprises forming a polymerization solution comprising a conductingpolymer, an acid, a detergent, water, and an oxidizing agent andstirring the polymerization solution. In some embodiments, theconducting polymer comprises polyaniline, poly(p-phenylene oxide),poly(p-phenylene sulfide), poly(3,4-ethylenedioxythiophene),polypyrrole, polythiophene, poly(3-alkythiophene),poly(3-methylthiophene), poly(3-hexylthiophene), or any combinationthereof.

In some embodiments, the conducting polymer is distilled. In someembodiments, the conducting polymer is distilled by steam. In someembodiments, the steam comprises water, petroleum, oil, lipids,petrochemicals, or any combination thereof.

In some embodiments, the mass of the conducting polymer is about 20milligrams (mg) to about 90 mg. In some embodiments, the mass of theconducting polymer is at least about 20 mg. In some embodiments, themass of the conducting polymer is at most about 90 mg. In someembodiments, the mass of the conducting polymer is about 20 mg to about30 mg, about 20 mg to about 40 mg, about 20 mg to about 50 mg, about 20mg to about 60 mg, about 20 mg to about 70 mg, about 20 mg to about 80mg, about 20 mg to about 90 mg, about 30 mg to about 40 mg, about 30 mgto about 50 mg, about 30 mg to about 60 mg, about 30 mg to about 70 mg,about 30 mg to about 80 mg, about 30 mg to about 90 mg, about 40 mg toabout 50 mg, about 40 mg to about 60 mg, about 40 mg to about 70 mg,about 40 mg to about 80 mg, about 40 mg to about 90 mg, about 50 mg toabout 60 mg, about 50 mg to about 70 mg, about 50 mg to about 80 mg,about 50 mg to about 90 mg, about 60 mg to about 70 mg, about 60 mg toabout 80 mg, about 60 mg to about 90 mg, about 70 mg to about 80 mg,about 70 mg to about 90 mg, or about 80 mg to about 90 mg.

In some embodiments, the acid is aqueous. In some embodiments, the acidcomprises a strong acid. In some embodiments, the strong acid comprisesperchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid,sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, nitricacid, chloric acid, or any combination thereof.

In some embodiments, the concentration of the acid is about 0.1 M toabout 0.5 M. In some embodiments, the concentration of the acid is atleast about 0.1 M. In some embodiments, the concentration of the acid isat most about 0.5 M. In some embodiments, the concentration of the acidis about 0.1 M to about 0.2 M, about 0.1 M to about 0.3 M, about 0.1 Mto about 0.4 M, about 0.1 M to about 0.5 M, about 0.2 M to about 0.3 M,about 0.2 M to about 0.4 M, about 0.2 M to about 0.5 M, about 0.3 M toabout 0.4 M, about 0.3 M to about 0.5 M, or about 0.4 M to about 0.5 M.

In some embodiments, the volume of the acid is about 0.1 milliliters(ml) to about 0.6 ml. In some embodiments, the volume of the acid is atleast about 0.1 ml. In some embodiments, the volume of the acid is atmost about 0.6 ml. In some embodiments, the volume of the acid is about0.1 ml to about 0.2 ml, about 0.1 ml to about 0.3 ml, about 0.1 ml toabout 0.4 ml, about 0.1 ml to about 0.5 ml, about 0.1 ml to about 0.6ml, about 0.2 ml to about 0.3 ml, about 0.2 ml to about 0.4 ml, about0.2 ml to about 0.5 ml, about 0.2 ml to about 0.6 ml, about 0.3 ml toabout 0.4 ml, about 0.3 ml to about 0.5 ml, about 0.3 ml to about 0.6ml, about 0.4 ml to about 0.5 ml, about 0.4 ml to about 0.6 ml, or about0.5 ml to about 0.6 ml.

In some embodiments, the detergent comprises, dioctyl sodiumsulfosuccinate, perfluorooctanesulfonate, perfluorobutanesulfonate,alkyl-aryl ether phosphates, alkyl ether phosphates, cetrimoniumbromide, cetylpyridinium chloride, benzalkonium chloride, benzethoniumchloride, dimethyldioctadecylammonium chloride,dioctadecyldimethylammonium bromide, octenidine dihydrochloride,octaethylene glycol monododecyl ether, pentaethylene glycol monododecylether, polypropylene glycol alkyl ethers, decyl glucoside, laurylglucoside, octyl glucoside, polyethylene glycol octylphenyl ethers,polyethylene glycol alkylphenyl ethers, nonoxynol-9, glycerol alkylesters, glyceryl laurate, polyoxyethylene glycol sorbitan alkyl esters,polysorbate sorbitan alkyl esters, dodecyldimethylamine oxide,poloxamers, polyethoxylated tallow amine, or any combination thereof.

In some embodiments, the mass of the detergent is about 1 mg to about 10mg. In some embodiments, the mass of the detergent is at least about 1mg. In some embodiments, the mass of the detergent is at most about 10mg. In some embodiments, the mass of the detergent is about 1 mg toabout 2 mg, about 1 mg to about 3 mg, about 1 mg to about 4 mg, about 1mg to about 5 mg, about 1 mg to about 6 mg, about 1 mg to about 7 mg,about 1 mg to about 8 mg, about 1 mg to about 9 mg, about 1 mg to about10 mg, about 2 mg to about 3 mg, about 2 mg to about 4 mg, about 2 mg toabout 5 mg, about 2 mg to about 6 mg, about 2 mg to about 7 mg, about 2mg to about 8 mg, about 2 mg to about 9 mg, about 2 mg to about 10 mg,about 3 mg to about 4 mg, about 3 mg to about 5 mg, about 3 mg to about6 mg, about 3 mg to about 7 mg, about 3 mg to about 8 mg, about 3 mg toabout 9 mg, about 3 mg to about 10 mg, about 4 mg to about 5 mg, about 4mg to about 6 mg, about 4 mg to about 7 mg, about 4 mg to about 8 mg,about 4 mg to about 9 mg, about 4 mg to about 10 mg, about 5 mg to about6 mg, about 5 mg to about 7 mg, about 5 mg to about 8 mg, about 5 mg toabout 9 mg, about 5 mg to about 10 mg, about 6 mg to about 7 mg, about 6mg to about 8 mg, about 6 mg to about 9 mg, about 6 mg to about 10 mg,about 7 mg to about 8 mg, about 7 mg to about 9 mg, about 7 mg to about10 mg, about 8 mg to about 9 mg, about 8 mg to about 10 mg, or about 9mg to about 10 mg.

In some embodiments, the volume of the water is about 9 ml to about 40ml. In some embodiments, the volume of the water is at least about 9 ml.In some embodiments, the volume of the water is at most about 40 ml. Insome embodiments, the volume of the water is about 9 ml to about 10 ml,about 9 ml to about 15 ml, about 9 ml to about 20 ml, about 9 ml toabout 25 ml, about 9 ml to about 30 ml, about 9 ml to about 35 ml, about9 ml to about 40 ml, about 10 ml to about 15 ml, about 10 ml to about 20ml, about 10 ml to about 25 ml, about 10 ml to about 30 ml, about 10 mlto about 35 ml, about 10 ml to about 40 ml, about 15 ml to about 20 ml,about 15 ml to about 25 ml, about 15 ml to about 30 ml, about 15 ml toabout 35 ml, about 15 ml to about 40 ml, about 20 ml to about 25 ml,about 20 ml to about 30 ml, about 20 ml to about 35 ml, about 20 ml toabout 40 ml, about 25 ml to about 30 ml, about 25 ml to about 35 ml,about 25 ml to about 40 ml, about 30 ml to about 35 ml, about 30 ml toabout 40 ml, or about 35 ml to about 40 ml.

In some embodiments, the oxidizing agent comprises ammonium persulfateand oxygen, ozone, hydrogen peroxide, fluorine, chlorine, halogens,nitric acid, sulfuric acid, peroxydisulfuric acid, peroxymonosulfuricacid, chlorite, perchlorate, hypochlorite, household bleach, chromicacid, dichromic acid, chromium trioxide, pyridinium chlorochromate,permanganate, sodium perborate, nitrous oxide, potassium nitrate, sodiumbismuthate, or any combination thereof. In some embodiments, theoxidizing agent is added in one portion.

In some embodiments, the concentration of the oxidizing agent is about0.1 M to about 0.5 M. In some embodiments, the concentration of theoxidizing agent is at least about 0.1 M. In some embodiments, theconcentration of the oxidizing agent is at most about 0.5 M. In someembodiments, the concentration of the oxidizing agent is about 0.1 M toabout 0.2 M, about 0.1 M to about 0.3 M, about 0.1 M to about 0.4 M,about 0.1 M to about 0.5 M, about 0.2 M to about 0.3 M, about 0.2 M toabout 0.4 M, about 0.2 M to about 0.5 M, about 0.3 M to about 0.4 M,about 0.3 M to about 0.5 M, or about 0.4 M to about 0.5 M.

In some embodiments, the mass of the oxidizing agent is about 1 mg toabout 10 mg. In some embodiments, the mass of the oxidizing agent is atleast about 1 mg. In some embodiments, the mass of the oxidizing agentis at most about 10 mg. In some embodiments, the mass of the oxidizingagent is about 1 mg to about 2 mg, about 1 mg to about 3 mg, about 1 mgto about 4 mg, about 1 mg to about 5 mg, about 1 mg to about 6 mg, about1 mg to about 7 mg, about 1 mg to about 8 mg, about 1 mg to about 9 mg,about 1 mg to about 10 mg, about 2 mg to about 3 mg, about 2 mg to about4 mg, about 2 mg to about 5 mg, about 2 mg to about 6 mg, about 2 mg toabout 7 mg, about 2 mg to about 8 mg, about 2 mg to about 9 mg, about 2mg to about 10 mg, about 3 mg to about 4 mg, about 3 mg to about 5 mg,about 3 mg to about 6 mg, about 3 mg to about 7 mg, about 3 mg to about8 mg, about 3 mg to about 9 mg, about 3 mg to about 10 mg, about 4 mg toabout 5 mg, about 4 mg to about 6 mg, about 4 mg to about 7 mg, about 4mg to about 8 mg, about 4 mg to about 9 mg, about 4 mg to about 10 mg,about 5 mg to about 6 mg, about 5 mg to about 7 mg, about 5 mg to about8 mg, about 5 mg to about 9 mg, about 5 mg to about 10 mg, about 6 mg toabout 7 mg, about 6 mg to about 8 mg, about 6 mg to about 9 mg, about 6mg to about 10 mg, about 7 mg to about 8 mg, about 7 mg to about 9 mg,about 7 mg to about 10 mg, about 8 mg to about 9 mg, about 8 mg to about10 mg, or about 9 mg to about 10 mg.

In some embodiments, the polymerization solution is stirred at roomtemperature.

In some embodiments, the polymerization solution is stirred for a periodof time of about 10 minutes to about 40 minutes. In some embodiments,the polymerization solution is stirred for a period of time of at leastabout 10 minutes. In some embodiments, the polymerization solution isstirred for a period of time of at most about 40 minutes. In someembodiments, the polymerization solution is stirred for a period of timeof about 10 minutes to about 15 minutes, about 10 minutes to about 20minutes, about 10 minutes to about 25 minutes, about 10 minutes to about30 minutes, about 10 minutes to about 35 minutes, about 10 minutes toabout 40 minutes, about 15 minutes to about 20 minutes, about 15 minutesto about 25 minutes, about 15 minutes to about 30 minutes, about 15minutes to about 35 minutes, about 15 minutes to about 40 minutes, about20 minutes to about 25 minutes, about 20 minutes to about 30 minutes,about 20 minutes to about 35 minutes, about 20 minutes to about 40minutes, about 25 minutes to about 30 minutes, about 25 minutes to about35 minutes, about 25 minutes to about 40 minutes, about 30 minutes toabout 35 minutes, about 30 minutes to about 40 minutes, or about 35minutes to about 40 minutes.

In some embodiments, the polymerization solution is stirred before theaddition of the oxidizing agent. In some embodiments, the polymerizationsolution is stirred by a magnetic stirrer.

In some embodiments, the step of synthesizing a nanotube on thefunctionalized carbon substrate comprises stirring the polymerizationfluid, immersing the functionalized carbon substrate in thepolymerization fluid, storing the functionalized carbon substrate in thepolymerization fluid, removing a functionalized carbon substrate fromthe polymerization fluid, washing the functionalized carbon substratewith water, and drying the functionalized carbon substrate. In someembodiments washing the functionalized carbon substrate with waterremoves excess polymerization fluid. In some embodiments, thefunctionalized carbon substrate is a polyaniline functionalized carbonsubstrate.

In some embodiments, polymerization fluid is stirred violently. In someembodiments, polymerization fluid is stirred non-violently. In someembodiments, the functionalized carbon substrate and the polymerizationfluid are stored without agitation. In some embodiments, thefunctionalized carbon substrate and the polymerization fluid are storedwith agitation.

In some embodiments, the polymerization fluid is stirred for a period oftime of about 15 seconds to about 60 seconds. In some embodiments, thepolymerization fluid is stirred for a period of time of at least about15 seconds. In some embodiments, the polymerization fluid is stirred fora period of time of at most about 60 seconds. In some embodiments, thepolymerization fluid is stirred for a period of time of about 15 secondsto about 20 seconds, about 15 seconds to about 25 seconds, about 15seconds to about 30 seconds, about 15 seconds to about 35 seconds, about15 seconds to about 40 seconds, about 15 seconds to about 45 seconds,about 15 seconds to about 50 seconds, about 15 seconds to about 55seconds, about 15 seconds to about 60 seconds, about 20 seconds to about25 seconds, about 20 seconds to about 30 seconds, about 20 seconds toabout 35 seconds, about 20 seconds to about 40 seconds, about 20 secondsto about 45 seconds, about 20 seconds to about 50 seconds, about 20seconds to about 55 seconds, about 20 seconds to about 60 seconds, about25 seconds to about 30 seconds, about 25 seconds to about 35 seconds,about 25 seconds to about 40 seconds, about 25 seconds to about 45seconds, about 25 seconds to about 50 seconds, about 25 seconds to about55 seconds, about 25 seconds to about 60 seconds, about 30 seconds toabout 35 seconds, about 30 seconds to about 40 seconds, about 30 secondsto about 45 seconds, about 30 seconds to about 50 seconds, about 30seconds to about 55 seconds, about 30 seconds to about 60 seconds, about35 seconds to about 40 seconds, about 35 seconds to about 45 seconds,about 35 seconds to about 50 seconds, about 35 seconds to about 55seconds, about 35 seconds to about 60 seconds, about 40 seconds to about45 seconds, about 40 seconds to about 50 seconds, about 40 seconds toabout 55 seconds, about 40 seconds to about 60 seconds, about 45 secondsto about 50 seconds, about 45 seconds to about 55 seconds, about 45seconds to about 60 seconds, about 50 seconds to about 55 seconds, about50 seconds to about 60 seconds, or about 55 seconds to about 60 seconds.

In some embodiments, the functionalized carbon substrate is stored inthe polymerization fluid at a temperature of about 10° C. to about 50°C. In some embodiments, the functionalized carbon substrate is stored inthe polymerization fluid at a temperature of at least about 10° C. Insome embodiments, the functionalized carbon substrate is stored in thepolymerization fluid at a temperature of at most about 50° C. In someembodiments, the functionalized carbon substrate is stored in thepolymerization fluid at a temperature of about 10° C. to about 15° C.,about 10° C. to about 20° C., about 10° C. to about 25° C., about 10° C.to about 30° C., about 10° C. to about 35° C., about 10° C. to about 40°C., about 10° C. to about 45° C., about 10° C. to about 50° C., about15° C. to about 20° C., about 15° C. to about 25° C., about 15° C. toabout 30° C., about 15° C. to about 35° C., about 15° C. to about 40°C., about 15° C. to about 45° C., about 15° C. to about 50° C., about20° C. to about 25° C., about 20° C. to about 30° C., about 20° C. toabout 35° C., about 20° C. to about 40° C., about 20° C. to about 45°C., about 20° C. to about 50° C., about 25° C. to about 30° C., about25° C. to about 35° C., about 25° C. to about 40° C., about 25° C. toabout 45° C., about 25° C. to about 50° C., about 30° C. to about 35°C., about 30° C. to about 40° C., about 30° C. to about 45° C., about30° C. to about 50° C., about 35° C. to about 40° C., about 35° C. toabout 45° C., about 35° C. to about 50° C., about 40° C. to about 45°C., about 40° C. to about 50° C., or about 45° C. to about 50° C.

In some embodiments, the functionalized carbon substrate is stored inthe polymerization fluid for a period of time of about 8 hours to about70 hours. In some embodiments, the functionalized carbon substrate isstored in the polymerization fluid for a period of time of at leastabout 8 hours. In some embodiments, the functionalized carbon substrateis stored in the polymerization fluid for a period of time of at mostabout 70 hours. In some embodiments, the functionalized carbon substrateis stored in the polymerization fluid for a period of time of about 8hours to about 10 hours, about 8 hours to about 20 hours, about 8 hoursto about 30 hours, about 8 hours to about 40 hours, about 8 hours toabout 50 hours, about 8 hours to about 60 hours, about 8 hours to about70 hours, about 10 hours to about 20 hours, about 10 hours to about 30hours, about 10 hours to about 40 hours, about 10 hours to about 50hours, about 10 hours to about 60 hours, about 10 hours to about 70hours, about 20 hours to about 30 hours, about 20 hours to about 40hours, about 20 hours to about 50 hours, about 20 hours to about 60hours, about 20 hours to about 70 hours, about 30 hours to about 40hours, about 30 hours to about 50 hours, about 30 hours to about 60hours, about 30 hours to about 70 hours, about 40 hours to about 50hours, about 40 hours to about 60 hours, about 40 hours to about 70hours, about 50 hours to about 60 hours, about 50 hours to about 70hours, or about 60 hours to about 70 hours.

In some embodiments, the functionalized carbon substrate is dried at atemperature of about 30 hours to about 120 hours. In some embodiments,the functionalized carbon substrate is dried at a temperature of atleast about 30 hours. In some embodiments, the functionalized carbonsubstrate is dried at a temperature of at most about 120 hours. In someembodiments, the functionalized carbon substrate is dried at atemperature of about 30 hours to about 40 hours, about 30 hours to about50 hours, about 30 hours to about 60 hours, about 30 hours to about 70hours, about 30 hours to about 80 hours, about 30 hours to about 90hours, about 30 hours to about 100 hours, about 30 hours to about 110hours, about 30 hours to about 120 hours, about 40 hours to about 50hours, about 40 hours to about 60 hours, about 40 hours to about 70hours, about 40 hours to about 80 hours, about 40 hours to about 90hours, about 40 hours to about 100 hours, about 40 hours to about 110hours, about 40 hours to about 120 hours, about 50 hours to about 60hours, about 50 hours to about 70 hours, about 50 hours to about 80hours, about 50 hours to about 90 hours, about 50 hours to about 100hours, about 50 hours to about 110 hours, about 50 hours to about 120hours, about 60 hours to about 70 hours, about 60 hours to about 80hours, about 60 hours to about 90 hours, about 60 hours to about 100hours, about 60 hours to about 110 hours, about 60 hours to about 120hours, about 70 hours to about 80 hours, about 70 hours to about 90hours, about 70 hours to about 100 hours, about 70 hours to about 110hours, about 70 hours to about 120 hours, about 80 hours to about 90hours, about 80 hours to about 100 hours, about 80 hours to about 110hours, about 80 hours to about 120 hours, about 90 hours to about 100hours, about 90 hours to about 110 hours, about 90 hours to about 120hours, about 100 hours to about 110 hours, about 100 hours to about 120hours, or about 110 hours to about 120 hours.

Other goals and advantages of the methods and devices taught herein willbe further appreciated and understood when considered in conjunctionwith the following description and accompanying drawings. While thefollowing description may contain specific details describing particularembodiments of the methods and devices taught herein, this should not beconstrued as limitations to the scope of the methods and devices taughtherein but rather as an exemplification of preferable embodiments. Foreach aspect of the methods and devices taught herein, many variationsare possible as suggested herein that are known to those of ordinaryskill in the art. A variety of changes and modifications may be madewithin the scope of the methods and devices taught herein withoutdeparting from the spirit thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the methods and devices taught herein are setforth with particularity in the appended claims. A better understandingof the features and advantages of the present methods and devices taughtherein will be obtained by reference to the following detaileddescription that sets forth illustrative embodiments, in which theprinciples of the methods and devices taught herein are utilized, andthe accompanying drawings or figures (also “FIG.” and “FIGS.” herein),of which:

FIG. 1A illustratively depicts electron and ion transfer pathways in ananofiber morphology of polyaniline, in accordance with someembodiments.

FIG. 1B illustratively depicts electron and ion transfer pathways in ananosphere morphology of polyaniline (PANI), in accordance with someembodiments.

FIG. 1C illustratively depicts electron and ion transfer pathways in ananotube morphology of polyaniline, in accordance with some embodiments.

FIG. 2 illustratively depicts an exemplary asymmetric device, inaccordance with some embodiments.

FIG. 3 illustratively depicts an exemplary process of functionalizingcarbon cloth, in accordance with some embodiments.

FIG. 4 illustratively depicts an example of the bonds that changethrough the connection between PANI and functionalized carbon cloth(FCC), in accordance with some embodiments.

FIG. 5A displays exemplary field emission scanning electron microscope(FESEM) images of PANI synthesized on carbon cloth (CC) in the presenceof sodium dodecyl sulfate (SDS), in accordance with some embodiments.

FIG. 5B displays exemplary FESEM images of PANI synthesized on CC in thepresence of SDS, in accordance with some embodiments.

FIG. 6A displays an exemplary FESEM image of the surface structure of aCC, in accordance with some embodiments.

FIG. 6B displays an exemplary FESEM image of a 16-hour polymerizedPANI-CC in high magnification, in accordance with some embodiments.

FIG. 6C displays an exemplary FESEM image of a 16-hour polymerizedPANI-CC in low magnification, in accordance with some embodiments.

FIG. 6D displays an exemplary FESEM image of a 20-hour polymerizedPANI-CC, in accordance with some embodiments.

FIG. 6E displays an exemplary FESEM image of a 24-hour polymerizedPANI-CC in low magnification, in accordance with some embodiments.

FIG. 6F displays an exemplary FESEM image of a 24-hour polymerizedPANI-CC in high magnification, in accordance with some embodiments.

FIG. 6G displays an exemplary FESEM image of a 28-hour polymerizedPANI-CC, in accordance with some embodiments.

FIG. 6H displays an exemplary FESEM image of a 32-hour polymerizedPANI-CC, in accordance with some embodiments.

FIG. 7 displays exemplary cyclic voltammetry (CV) graphs of exemplary CCand PANI-CC devices, in accordance with some embodiments.

FIG. 8 displays exemplary galvanostatic charge-discharge curves of anexemplary symmetric PANI-CC device, in accordance with some embodiments.

FIG. 9 displays exemplary CV curves of exemplary PANI-CC symmetricdevices with different polymerization times, in accordance with someembodiments.

FIG. 10 displays exemplary galvanostatic charge-discharge curves ofexemplary PANI-CC symmetric devices with different polymerization times,in accordance with some embodiments.

FIG. 11 displays exemplary powder x-ray diffraction (XRD) patterns ofexemplary carbon cloth and functionalized carbon cloth, in accordancewith some embodiments.

FIG. 12 displays exemplary Fourier transform infrared (FTIR)spectroscopy spectrum measurements of exemplary PANI-FCC and PANI-CCelectrodes, in accordance with some embodiments.

FIG. 13A displays exemplary CV curves of an exemplary PANI-FCC symmetricsupercapacitor at a scan rate of 100 mV/s, in accordance with someembodiments.

FIG. 13B displays exemplary charge-discharge (CD) curves of an exemplaryPANI-FCC symmetric supercapacitor at a current density of 1 A/g, inaccordance with some embodiments.

FIG. 13C displays an exemplary Nyquist plot of CC, FCC, PANI-CC andPANI-FCC, in accordance with some embodiments.

FIG. 13D displays an exemplary Bode plot of CC, FCC, PANI-CC andPANI-FCC, in accordance with some embodiments.

FIG. 13E displays exemplary CV curves of an exemplary PANI-FCC symmetricsupercapacitor under scan rates from 20 mV/s to 1000 mV/s, in accordancewith some embodiments.

FIG. 13F displays exemplary CD profiles of an exemplary PANI-FCCsymmetric supercapacitor at various current densities ranging from 1 to50 A/g, in accordance with some embodiments.

FIG. 13G displays exemplary calculated capacitances as a function ofcurrent density of exemplary PANI-FCC and PANI-CC devices, in accordancewith some embodiments.

FIG. 13H displays the exemplary cyclability of an exemplary PANI-FCCdevice at current densities of 1 to 20 A/g−1 over 5000 cycles, inaccordance with some embodiments.

FIG. 14 displays exemplary CD curves of an exemplary PANI-FCC device atdifferent currents, in accordance with some embodiments.

FIG. 15A displays exemplary CD curves of an exemplary carbon cloth.

FIG. 15B displays exemplary Nyquist plots of a PANI-FCC electrodes ofvarious annealing times.

FIG. 16A displays an exemplary relationship between the resistance andthe bending angle of an exemplary PANI-FCC device.

FIG. 16B displays an exemplary relationship between the resistance andthe number of bending cycles of an exemplary PANI-FCC device, inaccordance with some embodiments.

FIG. 16C displays exemplary CV curves of an exemplary bent, flat, andreopened PANI-FCC device, in accordance with some embodiments.

FIG. 17A displays exemplary CV curves of exemplary three-electrodePANI-FCC and AC-FCC devices at 20 mV/s, in accordance with someembodiments.

FIG. 17B displays an exemplary CV curve of an exemplary PANI-FCCasymmetric device at 50 mV/s, in accordance with some embodiments.

FIG. 17C displays exemplary CD curves of an exemplary asymmetric SC atvarious current densities, in accordance with some embodiments.

FIG. 17D displays exemplary Ragone plots of exemplary symmetric andasymmetric devices under various current densities, in accordance withsome embodiments.

FIG. 18A displays exemplary CV curves of an exemplary PANI-FCCasymmetric device at different potential windows, in accordance withsome embodiments.

FIG. 18B displays exemplary CV curves of an exemplary PANI-FCCasymmetric device at 50 mV/s and in H₂SO₄ and NQ gel electrolytes, inaccordance with some embodiments.

FIG. 18C displays exemplary Nyquist plot of an exemplary PANI/AC device,in accordance with some embodiments.

FIG. 18D displays exemplary discharge curves of an exemplary PANI-FCCasymmetric device at different current densities from 2 to 50 A/g, inaccordance with some embodiments.

FIG. 18E displays the calculated capacitance as a function of currentdensity for an exemplary PANI/AC device from 5 to 50 A/g, in accordancewith some embodiments.

FIG. 18F displays an exemplary Ragone plot of exemplary symmetric andasymmetric devices, in accordance with some embodiments.

FIG. 19A displays exemplary CV curves of exemplary PANI-FCC and AC-FCCelectrodes, in accordance with some embodiments.

FIG. 19B displays exemplary CD curves of exemplary PANI-FCC and AC-FCCelectrodes in the presence of NQ at a current density of 10 A/g, inaccordance with some embodiments.

FIG. 19C displays exemplary CD curves of exemplary AC-FCC//PANI-FCCdevices in the presence of NQ at different current densities, inaccordance with some embodiments.

FIG. 20A displays exemplary CV curves of an exemplary asymmetricAC-FCC//PANI-FCC device in an NQ gel electrolyte, in accordance withsome embodiments.

FIG. 20B displays exemplary charge and discharge curves of an exemplaryasymmetric AC-FCC//PANI-FCC device with and without NQ, in accordancewith some embodiments.

FIG. 20C displays the exemplary relationship between the current densityand the specific capacitance of an exemplary AC-FCC//PANI-FCC device inthe presence of NQ, in accordance with some embodiments.

FIG. 20D displays exemplary charge and discharge curves of an exemplaryasymmetric AC-FCC//PANI-FCC device under a current density of about 47A/g, in accordance with some embodiments.

FIG. 21 displays the exemplary relationship between the power densityand the energy density of exemplary symmetric and asymmetric devices, inaccordance with some embodiments.

FIG. 22 displays the gravimetric and volumetric energy densities of thecomponents of an exemplary electrochemical cell, in accordance with someembodiments.

FIG. 23A illustratively displays an exemplary red LED powered by twoexemplary asymmetric devices in series, in accordance with someembodiments.

FIG. 23B illustratively displays an exemplary a clock powered by twoexemplary asymmetric devices in series, in accordance with someembodiments.

DETAILED DESCRIPTION

The market for flexible electronics such as solar cell arrays, flexibledisplays, and wearable electronics is rapidly growing and contributingto the design of future electronics, due to their portability,ruggedness, bendability, and rollability. The recent rapid progress inthe production of flexible electronic devices over large areas, at thefraction of the cost of traditional semiconductors, has led to thedevelopment of various energy storage and power storage devices,including a wide array of flexible semiconductors of varying sizes,shapes, and mechanical properties.

As such, there are growing demands for flexible, solid-state energystorage devices that are compatible with next-generation printed andflexible electronics. To this effect, the active layer and interfacesbetween flexible components must be redesigned to replace the rigidcomponents of traditional supercapacitors (SCs). As such, improving theenergy density of SCs is necessary and will contribute to thetechnological advancement of energy storage devices.

Reducing the size, increasing the flexibility, and achieving a highenergy density, integrated with the intrinsic high power density andcyclability of supercapacitors constitutes a major step forward towardmore sustainable and efficient energy storage systems.

Therefore, a current unmet need exists for a battery device that iscapable of recharging in seconds, that provides power over long periodsof time, can be repeatedly bent without capability loss, and is asminiaturizable as other corresponding electronics components.

Provided herein are supercapacitor devices and methods for fabricationthereof. The supercapacitor devices may be electrochemical devices. Thesupercapacitor devices may be configured for high energy and powerdensity. The supercapacitor devices may include an electrode composed ofa rectangular-tube PANI that is chemically synthesized on afunctionalized carbon cloth (FCC) substrate, and immobilized on acurrent collector. The supercapacitor devices may be arranged assymmetric, asymmetric, or 3D capacitors devices which contain anelectrode immobilized on a current collector. The supercapacitor devicesof the disclosure may comprise interconnected devices.

The present disclosure additionally provides systems and methods forgrowing polyaniline nanotubes on carbon cloth. The processing mayinclude the manufacture (or synthesis) of functionalized carbon clothand/or the manufacture (or synthesis) of polyaniline nanotubes andnanostructures. Some embodiments provide methods, devices, and systemsfor the manufacture (or synthesis) of functionalized carbon cloth and/orfor the manufacture (or synthesis) of polyaniline nanotubes andnanostructures and/or for the manufacture (or synthesis) of electrolytesand/or for the manufacture (or synthesis) of supercapacitors. Variousaspects of the disclosure described herein may be applied to any of theparticular applications set forth below or in any other type ofmanufacturing, synthesis, or processing setting. Other manufacturing,synthesis, or processing of materials may equally benefit from featuresdescribed herein. For example, the methods, devices, and systems hereinmay be advantageously applied to manufacture (or synthesis) of variousforms of functionalized carbon. The methods and devices taught hereinmay be applied as a stand-alone method, device, or system, or as part ofan integrated manufacturing or materials (e.g., chemicals) processingsystem. It shall be understood that different aspects of the methods anddevices taught herein may be appreciated individually, collectively, orin combination with each other.

The present disclosure further provides an exemplary energy storagedevice fabricated from rectangular-tube polyaniline (PANI) that ischemically synthesized. The rectangular-tube PANI, as an activematerial, is synthesized on a functionalized carbon cloth (FCC) as asubstrate, and the obtained composite is immobilized on a stainlesssteel mesh as a current collector. The present disclosure additionallypresents a technique for the direct synthesis of PANI nanotubes, withrectangular pores, on chemically activated CC.

The supercapacitors described herein may play an important role in oneor more applications or areas, such as, but not limited to, portableelectronics (e.g., cellphones, computers, cameras, etc.), medicaldevices (e.g., life-sustaining and life-enhancing medical devices,including pacemakers, defibrillators, hearing aids, pain managementdevices, drug pumps), electric vehicles (e.g., batteries with longlifetime are needed to improve the electric vehicle industry), space(e.g., the batteries are used in space to power space systems includingrovers, landers, spacesuits, and electronic equipment), militarybatteries (e.g., the military uses special batteries for powering alarge number of electronics and equipment; reduced mass/volume of thebatteries described herein are highly preferred), electric aircraft(e.g., an aircraft that runs on electric motors rather than internalcombustion engines, with electricity coming from solar cells orbatteries), grid scale energy storage (e.g., batteries are used to storeelectrical energy during times when production, from power plants,exceeds consumption and the stored energy are used at times whenconsumption exceeds production), renewable energy (e.g., since the sundoes not shine at night and the wind does not blow at all times,batteries in off-the-grid power systems are capable of storing excesselectricity from renewable energy sources for use during hours aftersunset and when the wind is not blowing; high power batteries mayharvest energy from solar cells with higher efficiency than currentstate-of-the-art batteries), power tools (e.g., the batteries describedherein may enable fast-charging cordless power tools such as drills,screwdrivers, saws, wrenches, and grinders; current batteries have along recharging time), or any combination thereof.

Supercapacitors

Supercapacitors are high-power energy storage devices with a much highercapacitance than normal capacitors. Supercapacitors (SCs) have recentlyattracted considerable attention as high power density energy storageresources, and have been increasingly employed energy storage resourcesin portable electronic devices, regenerative braking systems, voltagestabilization devices, hybrid buses, medical devices, and hybridelectric vehicles.

In some embodiments, supercapacitors or electrochemical capacitors arecomprised of two or more electrodes separated by an ion-permeablemembrane (separator) and an electrolyte ionically connecting theelectrodes, whereas ions in the electrolyte form electric double layersof opposite polarity to the electrode's polarity when the electrodes arepolarized by an applied voltage.

In some embodiments, an electrode in an electrochemical cell comprisedof a substrate and an active material referred to as either an anode,whereas electrons leave the active material within cell and oxidationoccurs, or a cathode, whereas the electrons enter the active materialwithin cell and reduction occurs. Each electrode may become either theanode or the cathode depending on the direction of current through thecell. In some embodiments, the supercapacitors may be symmetric orasymmetric, wherein the electrodes are identical or dissimilar,respectively. In some embodiments, the supercapacitors are configuredwith two or more electrodes.

Supercapacitors store energy via three main mechanisms (i) electricdouble-layer capacitance (EDLC), (ii) Faradaic capacitance, and (iii)capacitance directly from redox active electrolytes. Via the first twomechanisms, only solid-phase electrode materials contribute to chargestorage, while the other cell components, including electrodes andelectrolyte, are electrochemically inert. The addition of a redox activespecies to the electrolyte enhances the cell's capacitance throughelectrochemical reactions at the electrode/electrolyte interface.

In some embodiments, the devices herein (e.g., supercapacitors and/ormicrosupercapacitors) may be configured in different structures. In someembodiments, the devices may be configured in stacked structures (e.g.,comprising stacked electrodes), planar structures (e.g., comprisinginterdigitated electrodes), spirally wound structures, or anycombination thereof. In some embodiments, the devices may be configuredin a sandwich structure or an interdigitated structure.

Electrodes

Materials commonly employed in supercapacitor electrodes includetransition-metal oxides, conducting polymers, and high-surface carbons.Unfortunately, however, conventional supercapacitors based on thesematerials may exhibit low energy densities, and are limited by the massloading of the electrode's active materials.

In some embodiments, faradaic materials are employed as electrodesbecause they store charge both on the surface and in the bulk, asopposed to EDLC materials, which only store charge through ionadsorption on the electrode's surface.

In some embodiments, high-surface-area electrodes are carbonaceous andcomprise carbon cloth, carbon fiber, amorphous carbon, glassy carbon,carbon nanofoam, carbon aerogel, or activated carbon (AC).

In some embodiments, AC refers to carbon that has been treated toincrease its surface area. In some embodiments, the crystalline densityof AC is about 0.5 g/cm³.

The conducting polymer polyaniline serves as an ideal charge storagematerial due to its low-cost, ease of synthesis, controllable electricalconductivity, large specific capacitance, and environmental stability.

Among the vast majority of supercapacitive component materials,polyaniline (PANI), and its different morphologies, have been used as anactive material because of its intrinsic high oxidation-reduction(redox) active-specific capacitance, flexibility, and ability to convertbetween multiple redox states accompanied by rapid doping and dedopingof counter ions during charge and discharge processes.

In some embodiments, polyaniline (PANI) is one example of asemi-flexible rod conducting polymer which is ease to synthesize, isenvironmentally stable, cheap, and exhibits a high electricalconductivity and specific pseudocapacitance. Additionally, PANI may bereadily converted between multiple redox states accompanied by rapiddoping and dedoping of counter ions during charge and dischargeprocesses and, as such, electron transfer in PANI is accomplishedthrough a conjugated double bond, passing of an electric current in acoherent wrap. Finally, in some embodiments, PANI exhibits an intrinsichigh oxidation-reduction (redox) active-specific capacitance andflexibility. Therefore, developing PANI-based hybrid electrodes has beenan attractive topic in the hope of improving its cycling stability.

Despite being a superior energy storage material, bulk PANI, in someembodiments, suffers from poor mechanical properties and mediocrecycling stability, whereas the large volume changes associated withdoping and dedoping of the counter ions destroy the polymer backboneover cycling thus dimishing capacity and limiting the potentialcommercial applications of PANI pseudocapacitors. As electron transferin PANI occurs through a conjugated double bond, however, passing anelectric current in a coherent wrap may be easier than electron transferbetween two independent parts.

In some embodiments, the structure and geometry of PANI is altered atthe nanoscale to relax its internal strain by allowing the small surfacefeatures free space to flex. In some embodiments, the PANI isfunctionalized, wherein new functions, features, capabilities, orproperties of a material are added by changing its surface chemistry andmorphology.

In some embodiments, the morphology of a faradaic electrode's materialshas a significant impact on the electrochemical performance. Someelectrode structures facilitate electron transfer in the activematerials and, therefore, increase the conductivity and capacity oftheir respective devices. Nanostructuring of electrode materialsrepresents an effective strategy towards altering the morphology of, andsignificantly improving the performance of, supercapacitor electrodes byincreasing the interfacial area between the electrode and theelectrolyte and by minimizing the ion diffusion pathway within theactive materials. In some embodiments, electrode nanostructuringadditionally minimizes the ion diffusion pathway within the activematerial.

In some embodiments, PANI has a crystalline density of about 1.3 g/cm³.

In some embodiments, the chemical and electrochemical properties of anelectrode are enhanced through the addition of surface functional groupswhich increase charge storage capacity via the pseudocapacitive effect.In some embodiments, functionalization alters the features,capabilities, or properties of a material by changing its surfacechemistry and morphology. Functionalization synthesizes several forms ofsurface nanostructures such as nanospheres, nanodiscs, nanowire,nanofibers, nanotubes, nanoplates, and nanoflowers. Among these,nanotube structures with small diameters allow for better accommodationof volume changes, and direct one-dimensional electronic pathway from asubstrate, to allow for efficient electron transport and, therefore,provide an increased electrical conductivity and capacity. Furthermore,the combined electrolyte-exposed nanotube external and internal surfaceareas enable high charge storage capacities, and provide strain reliefby increasing the free space available for surface flexing. Thisapproach addresses the stability issues of silicon anodes in lithium ionbatteries, which exhibit large volume changes during cycling.

In designing supercapacitor electrodes, special efforts may be made toprovide a high energy density and high power density, including theoptimization of the preparation conditions to facilitate ionic andelectronic transport within the electrodes, as illustrated in FIGS.1A-C. As such, the design of high-performance hybrid supercapacitorsrequires high-energy-high-power hybrid supercapacitor electrodes.

FIGS. 1A-C schematically illustrate high-energy-high-power hybridsupercapacitor electrode designs, with nanofiber 101, nanosphere, 102and nanotube morphologies 103, respectively, whereas the electrode witha nanotube morphology of PANI schematically displayed in FIG. 1C iscapable of improved facilitation of both the ionic current 102 (IC) andthe electronic current (EC), and thus may be capable of forming asupercapacitor with a high energy and a high power.

In some embodiments, electrodes with nanostructured morphologies exhibitan increased performance, whereas per FIGS. 1A-C, the porous structureof these electrodes increases the exposure area between the activematerial and the electrolyte, and thus increase the discharge areacompared to a solid electrode surface. Particularly, electrodes withnanotube morphologies allow for increased charge storage capacitybecause both the external and internal surfaces of a nanotube areexposed to an electrolyte.

Substrates

In some embodiments, carbon cloth (CC) is used as a cell substrate. Insome embodiments carbon cloth comprises a woven assembly of multiplecarbon fibers. In some embodiments, carbon fiber and graphite fiber arefibers composed mostly of carbon atoms. Additionally, the goodelectrical conductivity and flexibility of carbon cloth enables deviceswith low internal resistance (by providing short pathways for electrontransport) and mechanical flexibility.

In some embodiments, CC is an excellent three-dimensional conductiveskeleton that supports a high electrolytic-accessible surface area,provides a direct path for electron transfer, improves conductivity ofits composites, and relieves the degradation accompanied by volumechanges during cycling. Further, CC acts as an ideal substrate forflexible energy storage system because of its mechanical flexibility,porous structure, high electrical conductivity, short electron transportpathway, low internal resistance, high areal loading, and its ability tobe easily packaged.

In some embodiments, the chemical activation of carbon cloth is enhancedthrough hybridization, by synthesizing conductive polymer nanostructureson the surface of the electrode. In some embodiments, the chemical andelectrochemical properties of carbon cloth are modified to enhance theproperties of its composite hybrid, whereas the chemical activation ofCC, via the addition of functional groups onto the surface, enhances thecharge storage capacity via the pseudocapacitive effect. Additionally,the functional groups on the surface of the functionalized carbon clothallow for a stronger connection to the PANI, thus facilitating thepassage of electrons from the polymer to the substrate. In someembodiments, chemical activation of a CC aids in situ polymerization byconverting its naturally hydrophobic surface into a hydrophilic surfacecapable of increased interaction with a, typically aqueous,polymerization or monomer feed solution. In some embodiments, the insitu polymerization of a conductive polymer ensures direct electricalcontact with CC, thus eliminating the need for, and the extra weight of,binders and conductive additives.

An exemplary image of the surface structure of a CC 602 displays, perFIG. 6A, a morphology comprising fibrous structures. The optimal 3Dstructure of CC enables high areal loading of PANI, which is animportant parameter for commercially viable electrodes.

In some embodiments, carbon cloth has a crystalline density of about 1.6g/cm³.

Electrolytes

The energy storage devices described herein may comprise an electrolyte.Electrolytes herein may include, for example but not limited to,aqueous, organic, and ionic liquid-based electrolytes, which may be inthe form of a liquid, solid, or a gel. In some embodiments, anelectrolyte is a solution with a uniform dispersion of cations andanions formed from an electrically conductive solute dissolved in apolar solvent.

Although electrolytes are neutral in charge, applying an electricalpotential (voltage) to the solution draws the cations of the solution tothe electrode with an abundance of electrons, and the anions to theelectrode with an electron deficit. As such, the movement of anions andcations in opposite directions within the solution forms an energycurrent. Electrolytes described herein may comprise, for example,aqueous, organic, and/or ionic liquid-based electrolytes. Theelectrolyte may be a liquid, a solid, or a gel. An ionic liquid may behybridized with another solid component such as, for example, polymer orsilica (e.g., fumed silica), to form a gel-like electrolyte (also“ionogel” herein). An aqueous electrolyte may be hybridized with, forexample, a polymer, to form a gel-like electrolyte (also “hydrogel” and“hydrogel-polymer” herein). In some cases, a hydrogel electrolytesolidifies during device fabrication, which binds the cell's componentstogether to improve the mechanical and electrical properties of anelectrode. An organic electrolyte may be hybridized with, for example, apolymer, to form a gel-like electrolyte. In some embodiments, theelectrolyte may also include a lithium salt (e.g., LiPF₆, LiBF₄, orLiClO₄). For example, the electrolyte may include a lithium salt (e.g.,LiPF₆, LiBF₄, or LiClO₄) in an organic solution (e.g., ethylenecarbonate (EC), dimethyl carbonate (DMC), or diethyl carbonate (DEC).The electrolyte may comprise one or more additional components (e.g.,one or more additives) to form an electrolyte composition. In oneexample, a soft pack polymer LIB electrolyte comprises one or more ofEC, ethyl methyl carbonate (EMC), DEC, LiPF₆, and other additives. Inanother example, a high capacity LIB electrolyte may comprise one ormore of EC, DEC, propylene carbonate (PC), LiPF₆, and other additives.

Quinone electrolyte additives have been employed for their ability tostore 2 e⁻/2 H⁺ per quinone unit to enhance capacities in double-layersupercapacitors. During charge and discharge operations, quinoneadditives undergo redox processes at the electrodes. In someembodiments, quinone electrolytes are particularly excellentredox-active electrolytes because of their excellent electrochemicalreversibility during charge and discharge, small size, high mobility,and an acidic pH compatible with the current family of acid-dopedpolymers.

Supercapacitor Device Design

In some embodiments, energy storage devices with ultrahigh energydensities are designed by selecting an electrode material in combinationwith an electrolyte to attain synergistic interactions among thedevice's components. Faradaic energy storage materials in currentthree-electrode devices require aqueous electrolytes for their operationwhich are limited to about 1.0 V due to the decomposition of water at1.23 V. Although symmetric devices exhibit a max theoretical voltagewindow of 1.0 V, asymmetric devices attain the voltage window of aqueouselectrolytes by extending their operating voltage beyond thethermodynamic decomposition voltage of water.

In some embodiments, a supercapacitor device that comprises PANI, whichis capable of being converted between multiple redox states, as anelectrochemically active material and a 1,4-naphthoquinone (NQ) redoxcouple electrolyte, forms a tunable double redox shuttle, whereas NQprovides pseudocapacitance through direct redox reactions on theelectrode surfaces, catalyzes the regeneration of the oxidized form ofPANI, and operates as a redox shuttle for the reversibleoxidation/reduction of polyaniline, to considerably enhance the overallperformance of the device.

The 3D nature of polyaniline rectangular tubes supported on afunctionalized carbon cloth offers efficient electron and ion transportpathways and provides sufficient space for the addition of NQ, thusforming a second redox system, and thus a tunable redox shuttle in theelectrolyte that enhances electron-transfer processes on the surface ofthe electrode. Further, the addition of NQ not only increases thecapacitance of polyaniline electrodes, but also improves the capacitanceof EDLC supercapacitor materials, such as activated carbons.

As such, the use of NQ, through an electrocatalytic mechanism as a redoxadditive, enables multiple charge transfer processes, provides Faradaiccapacitance with direct redox reactions on the electrode surfaces,serves as the basis for a regenerative pathway towards long-termutilization of the electrode active materials, and enables asupercapacitor device with a much higher energy density. In someembodiments, NQ has a crystalline density of about 1.4 g/cm³.

FIG. 2 shows the composition of an exemplary supercapacitor 200, whereasthe positive electrode 201 and the negative electrode 202 are separatedby an ion-and-molecule-permeable membrane 203 that is soaked in an NQelectrolyte comprising sulfuric acid (H₂SO₄) and acetic acid (AcOH).

In some embodiments, the NQ comprises a polyvinyl alcohol (PVA) gelelectrolyte in 1 M H₂SO₄ with 30% acetic acid (AcOH). In someembodiments a polyvinyl alcohol (PVA) gel electrolyte is formed bydissolving 1 g of PVA in 10 mL of deionized water and AcOH, vigorouslystirring for 30 minutes, adding a 0.56 mL stoke of H₂SO₄ and adding 1.53mg of NQ.

The NQ-promoted regeneration of polyaniline (PANI), which is capable ofbeing reused in multiple redox reactions, plays an important role in asupercapacitor device. FIG. 4 displays the chemical process ofconverting a functionalized carbon cloth into a PANI functionalizedcarbon cloth, wherein per FIG. 2 and the equations below, PANI_(ox) iselectrochemically reduced to PANI_(red) on the electrode surface, and NQin the electrolyte oxidizes back the reduced form of the PANI via an EC′regenerative mechanism that may then re-undergo electron transferreactions on the surface.

${{PANI}_{ox} + {2e} + {2H^{+}}}\underset{charge}{\overset{discharge}{\rightleftarrows}}{PANI}_{red}$${{PANI}_{red} + {NQ}}\underset{charge}{\overset{discharge}{\rightleftarrows}}{{PANI}_{ox} + {H_{2}{NQ}}}$H₂NQ ⇄ NQ + 2e + 2H⁺

As such, the Faradaic capacitance of the device increases considerablydue to the multiple reuse of the appropriate form (depending on thecharge and discharge process) of polyaniline as a starting electroactivematerial. In addition to its electrocatalytic regenerative mechanism, NQmay undergo redox reactions on the substrate's surfaces. Thecombinatorial effect of NQ as both a tunable redox shuttle and a redoxadditive increases the performance of the supercapacitor, since energyis stored both on the polyaniline surfaces using a pseudo-capacitivemechanism and in the electrode-electrolyte interface via the redoxreaction. There are several advantages as a result of theelectrocatalytic reaction, which provides in situ regeneration of theelectrode active materials. First, since Q=mnF, regeneration of thestarting active materials increases the value of m, thus providing anadditional charge in the cell. Additionally, because catalyticregeneration of the active material attains a higher current withoutincreasing the initial mass of the active materials, reducing the massof inactive components increases the specific energy and capacitance.Further, because additional mass is not required to increasecapacitance, the system's equivalent series resistance (ESR) remainslow. Moreover, because the regenerated active materials are firmlyimmobilized on the substrate surfaces, the ESR of the system does notincrease. Also, since current is a function of the surface concentrationof the active material (C_(AM)), the electrocatalytic regeneration ofthe electrode active material via an EC′ mechanism remarkably increasesthe C_(AM). Finally, the electrocatalytic reaction eliminates therequirement to diffuse the electroactive materials from the bulk of thesolution to the electrode surface.

Methods of Fabricating Electrodes

An exemplary process of fabricating a supercapacitor device 300comprising fabricating a polyaniline functionalized electrode andpackaging the electrode is shown in FIG. 3.

In exemplary embodiments, a method of fabricating a polyanilinefunctionalized electrode 305 comprises functionalizing a carbonsubstrate 301 to form a functionalized carbon substrate 303, preparingthe functionalized carbon substrate 303, formulating a polymerizationfluid 304, and synthesizing a polyaniline nanotube 306 on thefunctionalized carbon substrate.

In exemplary embodiments, the step of functionalizing a carbon substrate301 to form a functionalized carbon substrate 303 comprises forming afunctionalization solution 302, heating the functionalization solution302, cooling the functionalization solution 302, displacing a piece ofthe carbon substrate 301 into the functionalization solution 302, andrinsing a piece of functionalized carbon substrate 303.

In an exemplary embodiment, the functionalization solution 302 comprisesnitric acid (HNO₃) and sulfuric acid (H₂SO₄), wherein the volumetricpercentage of nitric acid in the functionalization solution 302 is about15% to about 60%. In an example, the functionalization solution 302comprises a volumetric percentage of nitric acid of about 33%.

In an exemplary embodiment, the functionalization solution 302 is heatedat a suitable temperature, such as, at about 30° C. to about 120° C. Inan example, the functionalization solution 302 is heated at atemperature of about 60° C. In an exemplary embodiment, the carbonsubstrate 301 is immersed in the functionalization solution 302 for asuitable period of time, such as, about 60 minutes to about 240 minutes.In an example, carbon substrate 301 is immersed in the functionalizationsolution 302 for a period of time of about 120 minutes.

In exemplary embodiments, the step of preparing the functionalizedcarbon substrate 303 comprises cutting a piece of the functionalizedcarbon substrate 303, submerging the piece of functionalized carbonsubstrate 303 in a polymerization fluid 304, sonicating the piece offunctionalized carbon substrate 303 in the polymerization fluid 304, anddrying the piece of functionalized carbon substrate 303.

In an exemplary embodiment, the functionalized carbon substrate 303 hasa suitable geometric surface area, such as about 0.1 cm² to about 0.5cm². In an example, the functionalized carbon substrate 303 has asuitable geometric surface area of about 0.25 cm².

In some embodiments, the polyaniline functionalized carbon substrate 305is then annealed in a furnace, in an air atmosphere, at 200° C. In anexemplary embodiment, the polyaniline functionalized carbon substrate305 is annealed for a suitable period of time of about 0.5 hours toabout 14 hours. In an example, the polyaniline functionalized carbonsubstrate 305 is annealed for a period of time of about 4 hours.

In an exemplary embodiment, the polymerization fluid 304 comprisesacetone and ethanol. In an exemplary embodiment, the polymerizationfluid 304 comprises a suitable volume percentage of acetone, such as,about 25% to about 100%. In an example, the volumetric percentage ofacetone in the polymerization fluid 304 is about 50%.

In an exemplary embodiment, the functionalized carbon substrate 303 issonicated for a suitable period of time, such as, about 15 minutes toabout 60 minutes. In an example, the functionalized carbon substrate 303is sonicated for a period of time of about 30 minutes.

In an exemplary embodiment, the functionalized carbon substrate 303 isdried at a suitable temperature, such as, at about 20° C. to about 120°C. In an example, functionalized carbon substrate 303 is dried at atemperature of about 60° C.

In an exemplary embodiment, the functionalized carbon substrate 303 isdried for a suitable period of time of about 3 hours to about 12 hours.In an example, the functionalized carbon substrate 303 is dried for aperiod of time of about 6 hours.

In exemplary embodiments, the step of formulating a polymerization fluid304 comprises mixing polyaniline, an acid, a detergent, water, and anoxidizing agent; and stirring the polymerization solution 304. In anexemplary embodiment, the acid comprises hydrochloric acid (HCl), thedetergent comprises sodium dodecyl sulfate (SDS), and the oxidizingagent comprises ammonium persulfate (APS).

In an exemplary embodiment, the polymerization fluid 304 comprises asuitable mass of polyaniline of about 20 mg to about 90 mg. In anexample, the mass of polyaniline in the polymerization fluid 304 isabout 45 mg.

In an exemplary embodiment, the polymerization fluid 304 comprises asuitable concentration of hydrochloric acid (HCl) of about 0.1 M toabout 0.5 M. In an example, the concentration of HCl in thepolymerization fluid 304 is about 0.25 M. In an exemplary embodiment,the polymerization fluid 304 comprises a suitable volume of HCl of about0.1 ml to about 0.6 ml. In an example, the volume of HCl in thepolymerization fluid 304 is about 0.3 ml.

In an exemplary embodiment, the polymerization fluid 304 comprises asuitable mass of SDS of about 1 mg to about 10 mg. In an example, theconcentration of SDS in the polymerization fluid 304 is about 5 mg.

In some embodiments the water comprises deionized water. In an exemplaryembodiment, the polymerization fluid 304 comprises a suitable volume ofwater of about 9 ml to about 40 ml. In an example, the volume of waterin the polymerization fluid 304 is about 18 ml.

In an exemplary embodiment, the polymerization fluid 304 comprises asuitable concentration of APS of about 0.1 M to about 0.5 M. In anexample, the concentration of APS in the polymerization fluid 304 isabout 0.24 M. In an exemplary embodiment, the polymerization fluid 304comprises a suitable volume of APS of about 1 ml to about 4 ml. In anexample, the concentration of APS in the polymerization fluid 304 isabout 2 ml.

In an exemplary embodiment, the polymerization fluid 304 is stirred fora suitable amount of time of about 10 minutes to about 40 minutes. In anexample, the polymerization fluid 304 may be stirred for a period ofabout 20 minutes.

In exemplary embodiments, the step of synthesizing a polyanilinenanotube 306 on the functionalized carbon substrate 303 comprisesagitating the polymerization fluid 304, immersing the functionalizedcarbon substrate 303 in the polymerization fluid 304, storing thefunctionalized carbon substrate 303 in the polymerization fluid 304,removing a polyaniline functionalized carbon substrate 305 from thepolymerization fluid 304, washing the polyaniline functionalized carbonsubstrate 305, and drying the polyaniline functionalized carbonsubstrate 305.

In an exemplary embodiment, the polymerization fluid 304 is agitated fora suitable amount of time of about 15 seconds to about 60 seconds. In anexample, the polymerization fluid 304 may be agitated for a period ofabout 30 seconds.

In an exemplary embodiment, the functionalized carbon substrate 303 isstored in the polymerization fluid 304 at a suitable temperature ofabout 10° C. to about 50° C. In an example, the functionalized carbonsubstrate 303 is stored in the polymerization fluid 304 at a temperatureof about 25° C.

In an exemplary embodiment, the functionalized carbon substrate 303 isstored in the polymerization fluid 304 for a suitable polymerizationtime of about 8 hours to 70 hours. In an example, the functionalizedcarbon substrate 303 is stored in the polymerization fluid 304 for apolymerization time of about 24 hours.

In an exemplary embodiment, the polyaniline functionalized carbonsubstrate 305 is dried at a suitable temperature of about 30° C. toabout 120° C. In an example, the polyaniline functionalized carbonsubstrate 305 is dried at a temperature of about 60° C.

In some embodiments, the polyaniline functionalized carbon substrate 305is used directly as SC electrodes without the need for binders orconductive additives typically used in conventional devices.

Finally, in an exemplary embodiment, the polyaniline functionalizedcarbon substrate 305 is packaged into a symmetric supercapacitor device300 whereas a separator, soaked in an electrolyte, is sandwiched betweenthe PANI faces of two polyaniline functionalized carbon substrates 305.

The PANI functionalized cloths as electrodes, along with a stainlesssteel current collector and an electrolyte form symmetric(PANI-FCC//PANI-FCC or PANI-CC//PANI-CC) and asymmetric (PANI-FCC//AC)supercapacitor devices.

Characterization and Measurements

The structure and morphology of the different electrode materials may beexamined using field-emission scanning electron microscopy (Philips andJEOL-JSM-6700). The structural changes before and afterfunctionalization of CC in the strong acid mixture may be characterizedusing an x-ray powder diffraction (Philips X'pert diffractometer with CoKα radiation [λ=0.178 nanometers] generated at 40 kV and 40 mA with astep size of 0.02° s⁻¹). A spectrophotometer (Tensor 27 Bruker) may beused for performing Fourier transform infrared (FTIR) spectroscopy.

The exemplary devices are tested for their electrochemical performanceusing cyclic voltammetry (CV), galvanostatic charge-discharge (CD)curves, and electrochemical impedance spectroscopy (EIS) experiments. ABiologic potentiostat (SP-300) may be used to acquire cyclic voltammetryand electrochemical impedance spectroscopy data for the differentdevices. A battery tester (Solartron) equipped with a Cell Test softwaremay be used for the galvanostatic CD studies.

In some embodiments, the processes described herein employ a magneticstirrer, which comprises a laboratory device, whereas an emittedrotating magnetic field quickly spins a magnetized stir bar immersed ina liquid for quick, consistent mixing.

All the chemicals used herein are used directly as purchased, withoutfurther purification. Aniline is distilled by water steam before use.

Effect of SDS on Surface Morphology and Performance

In some embodiments, the anionic surfactant, sodium dodecyl sulfate(SDS), plays an important role as a soft template in doping, in thepolymerization process upon the morphology of the synthesized PANI, andwith the electrochemical properties and capacitance of the device. TheSDS doping of the PANI structure generates a belt-like structure, therolling up of which takes place subsequently, wherein furtherpolymerization results in the formation of PANI with a rectangular-tubemorphology. In some embodiments, the low concentration of HCl triggersPANI polymerization in the medium with low acidity, which slows thereaction processes and may allow for the formation of nanostructures.

In an example, FIG. 5A shows that the morphology of PANI synthesized ona CC in the presence of SDS, is formed of rectangular nanotubes 502 withPANI nanoparticles on their surfaces, wherein FIG. 5B shows that themorphology of PANI synthesized on the CC in the absence of SDS iscomprised of irregular bulky nodules 503. Therefore, the PANI producedin the presence of SDS has rectangular shape with nanostructures on itssurface.

In an exemplary embodiment, the length of a rectangular nanotube 502synthesized on a CC in the presence of SDS is about 1 micrometers to 200micrometers. In an example, the length of a rectangular nanotube 502synthesized on a CC in the presence of SDS is about 1 micrometers.

In an exemplary embodiment, the outer diameter of a rectangular nanotube502 synthesized on a CC in the presence of SDS is about 100 nanometersto 1,000 nanometers. In an example, the outer width of a rectangularnanotube 502 synthesized on a CC in the presence of SDS is about 350nanometers.

In an exemplary embodiment, the inner diameter of a rectangular nanotube502 synthesized on a CC in the presence of SDS is about 50 nanometers to800 nanometers. In an example, the inner width of a rectangular nanotube502 synthesized on a CC in the presence of SDS is about 250 nanometers.

In an exemplary embodiment, a nanostructure on the surface of arectangular nanotube 502 synthesized on a CC in the presence of SDS is ananorod. In an exemplary embodiment, the nanorod on the surface of therectangular nanotube 502 has a length of about 4 micrometers to 50micrometers. In an example, the nanorod on the surface of therectangular nanotube 502 has a length of about 9 micrometers.

In an exemplary embodiment, the nanorod on the surface of a rectangularnanotube 502 synthesized on a CC in the presence of SDS has a width ofabout 20 nanometers to 120 nanometers. In an example, the nanorod on thesurface of a rectangular nanotube 502 synthesized on a CC in thepresence of SDS has a width of about 50 nanometers.

The regular hollow nanotube morphology increases electron transfer inthe PANI structure synthesized in the presence of SDS. The rectangularhollow nanotube morphology of the synthesized PANI, and the nanoparticlemorphology on its surface, enhances the electrochemical performance ofan electrode. Per the cyclic voltammograms of the exemplary CC andPANI-CC devices in FIG. 7, the redox peaks at 0.4 V and at 0.2 Vrepresent the reduction and oxidation, respectively, of PANI. The CVcurve of PANI-CC displays its pseudocapacitive behavior and confirms theelectric double-layer capacitance (EDLC) of CC in the exemplary device,and shows that the pseudocapacitance caused by PANI is dominant. Theexemplary CD curves show two plateaus in the CD steps which correspondwith the redox peaks of PANI in the exemplary CV curves. It is seen thatthe exemplary device, containing PANI synthesized in the presence SDS,exhibits a higher capacitance and rate capability per the areas underthe exemplary CV curves, and the discharge times in FIGS. 7 and 8,respectively. As such, a PANI-FCC exhibits a significantly highcharge/discharge current density and displays obvious redox peaks thatare assigned to the redox additive.

Effect of Polymerization Time on Surface Morphology and Performance

Examples of surface morphologies exhibited by PANI synthesized on CCover different polymerization times (16, 20, 24, 28, and 32 hours) areshown in FIGS. 6A-H. A 16-hour polymerized PANI-CC 601 a, per FIG. 6C inlow magnification, displays a morphology of hollow rectangularlycross-sectioned PANI nanotubes on the surface of a CC, with outerdiameters of about 200-500 nanometers, inner diameters of about 100-400nm, and lengths of several micrometers. Additionally, the 16-hourpolymerized PANI-CC 601 a, per FIG. 6B in high magnification, displays amorphology of nanorods disorderly aligned in hierarchical structures onthe surfaces of the PANI nanotubes, whose lengths and diameters rangefrom about 100-200 nanometers and about 40-60 nanometers, respectively.

An image of an exemplary 20-hour polymerized PANI-CC 601 b, as shown inFIG. 6D, exhibits a morphology of larger nanotubes, whose surfacescontain a greater size and quantity of nanorods.

An image of an exemplary 24-hour polymerized PANI-CC 601 c, as shown inFIGS. 6E and 6F at low and high magnifications, respectively, exhibits amorphology of poriferous nanotubes, whose surfaces contain a uniformarray of nanostructures that are 8-10 nanometers in size.

An image of an exemplary 28-hour polymerized PANI-CC 601 d and a 32-hourpolymerized PANI-CC 601 e, per FIGS. 6G and 6H, respectively, displaythat as the polymerization time increases, the nanostructures on therectangular tubes may aggregate as they grow.

FIGS. 9 and 10 display example CV and CD curves for the 16, 20, 24, 28,and 32-hour polymerized PANI-CCs in a symmetric PANI-CC device, whereasthe exemplary device comprising two 24-hour polymerized PANI-CCsexhibits the highest capacitance, of about 341 F/g, and the greatestdischarge time.

The increased capacitance of an exemplary device comprising a 24-hourpolymerized PANI-CC may be due to the fact that its rough surface, withmultiple smaller nanostructures whose diameters are between 8 nanometersand 10 nanometers, exhibits a greater surface area and a reduceddiffusion length.

Functionalization Characterization

Exemplary XRD patterns for CC and FCC are displayed in FIG. 11, whereasXRD patterns of pristine CC exhibit two main characteristic diffractionpeaks at 20° to 35° and 50° to 55° that are attributed to the (002) and(101) planes of the hexagonal CC structure. It is seen that CC's broadintensity peaks at 20° to 35° C. may greatly reduce due to thedestruction of the CC's ordered crystalline structure, and due to theincreased bond strength between C═N and COO— groups as their double bondis converted to a single bond during the functionalization process. Theinitial broad peak may be related to the —OH group of carboxylic acidfunctional group on the FCC, and the peak shift between the CC and theFCC may be explained by the stretching vibrations of C═C in thequinonoid and benzenoid rings, and the interaction of positive PANI C—Nband with the negative carboxylic acid.

Per FIG. 12, an example of Fourier transform infrared (FTIR) spectrumsof CC and PANI-FCC displays a strong and uniform connection between PANIand FCC, and thus provides evidence for a decreased equivalent seriesresistance and an increased conductance. As shown, after activation ofan exemplary CC, a broad peak appears between the range of 3,300 cm⁻¹ to3,650 cm⁻¹, which may indicate the presence of exchangeable protons,typically from carboxylic acid, alcohol, and amine functional groups, onthe FCC. The characteristic peaks of PANI may be modified byfunctionalizing the CC, whereas the bonds at 1,576 cm⁻¹ and 1,503 cm⁻¹corresponding to the stretching vibrations of C═C in the quinonoid andbenzenoid rings, respectively, shifted slightly to 1,580 cm⁻¹ and 1,507cm⁻¹. Additionally, the peak at 1,301 cm⁻¹, associated with C—Nstretching vibrations, experienced a large shift to 1,261 cm⁻¹ revealinga strong interaction of the positive PANI C—N band with the negativecarboxylic acid. Finally, the band at 1,240 cm⁻¹, associated with C—Nstretching vibrations of the exemplary device completely disappeared,which may indicate the formation of a covalent connection between theC═N and the COO— groups. Thus, FT-IR spectroscopy provides strongevidence for excellent connections between PANI and the FCC, and adecreased ESR, and thus an increased device conductance, which enablesgood power density at high rate charge-discharges, and improves thecycle life of a supercapacitor device.

Calculations

Capacitance is the ability of a body to store an electrical charge.Although any object may be electrically charged and exhibit capacitance,a body with a large capacitance holds more electric charge at a givenvoltage, than a body with a low capacitance. In some embodiments,capacitance is measured in Farads per gram (F/g).

The specific capacitance of the devices may be calculated through CDmeasurements using the following equation where C_(sp), is the specificcapacitance, I is the discharge current density (A), At is the dischargeduration (s), m is the mass loading (g), and ΔV is the potential range(V).

$C_{sp} = \frac{I\; \Delta \; t}{m\; \Delta \; V}$

The specific capacitance of a device with a non-linear CD curve, may becalculated using the following equation where C_(sp) is the specificcapacitance, I is the discharge current density (A), At is the dischargeduration (s), and V is the potential range (V).

$C_{sp} = \frac{2I{\int{Vdt}}}{V\; 2}$

To achieve the highest working potential range, the mass ratio of thenegative electrode to the positive electrode is determined according tothe charge balance theory (q⁺=q⁻). The voltammetric charges (Q) may becalculated based on the following equations where C_(single) is thespecific capacitance (F/g) of each electrode measured in athree-electrode setup (calculated from cyclic voltammograms at a scanrate of 10 mV s−1), ΔV is the potential window (V), and m is the mass ofthe electrode (g).

Q=C _(single) ×ΔV×m

To maintain a charge balance between the two electrodes, the mass ratiobetween the positive (m+) and negative (m−) electrodes needs to follow:

$\frac{m_{+}}{m_{-}} = \frac{c_{-} \times \Delta \; V_{-}}{c_{+} \times \Delta \; V_{+}}$

Energy density (ED) may be derived from the galvanostatic dischargecurves using the following equation where Csp is specific capacitance(F/g), and ΔV is the potential range (V).

${ED} = \frac{C_{sp}\Delta \; V^{2}}{2}$

The power density of the electrode is calculated from the followingequation where ED is the energy density in Wh/kg, and Δt is thedischarge time.

${PD} = \frac{ED}{\Delta \; t}$

Areal capacitance is the capacitance of a body per unit area. In someembodiments, areal capacitance is measured in Farads per cubiccentimeter (F/cm²)

Current density is the electric current per cross section area, definedas a vector whose magnitude is the electric current per cross-sectionalarea at a given point in space. In some embodiments, current density ismeasured in Amps per gram (A/g).

Energy density is a measure of the amount of energy that is stored perunit mass. In some embodiments, energy density is measured in Watt hoursper kilogram (Wh/kg).

Power density is a measure of the amount of power that is stored perunit mass. In some embodiments, power density is measured in kilowattsper kilogram (kW/kg).

Device Performance Characteristics

Electrochemical performance characteristics of an exemplary PANI-FCCdevice are shown in FIGS. 13A-H. As seen per the CV graph in FIG. 13A,pristine CC exhibits a small rectangular curve with a very lowcapacitance. The FCC displays a rectangular CV shape, with a higher EDLCcharge storage capability, possibly due to the fact that functionalizingthe carbon cloth increases its wettability, and thus facilitates theadsorption and desorption of charge. Additionally, the exemplaryPANI-FCC device exhibits a more rectangularly shaped CV, and thus ahigher capacitive performance, than the CV curve of the exemplaryPANI-CC device, per FIG. 13C. This performance improvement is mostlikely related to the exemplary PANI-FCC's increased charge storage inits double-layer mechanism, the wettability of the FCC, and theabsorption and desorption of charge. Additionally, it is clear that theredox peaks of the PANI that are responsible for the pseudocapacitanceof the device are covered by a capacitive portion resulting from FCC,and that the redox peaks of PANI, which are responsible for thepseudocapacitance of the device, are considerably diminished by theelectrical double-layer capacitance of the FCC.

As seen in FIG. 13B, an exemplary PANI-FCC device exhibits a moresymmetrically shaped CD curve, and thus a higher capacitive performance,than the PANI-CC, whose CD curve is shown in FIG. 13A. Additionally,FIG. 13B displays that the infrared (IR) drop in the discharge step ofthe exemplary PANI-FCC device is much smaller than the infrared (IR)drop in the discharge step of the exemplary FCC and CC devices, mostlikely due to the increased wettability of the carbon substrate and thestronger connection between the PANI and the FCC. As functionalizationof the CC may form some carboxylic acid groups with a negative charge,an electrostatic interaction may occur between the carboxylic acidgroups and the anilinium ions while the FCC is immersed in thepolymerization fluid. Thus, the connection between PANI and the FCC isstronger than the connection between the PANI and the CC, and more PANIis precipitated on FCC. This improvement in the capacity is most likelydue to the increased interaction between PANIs and the functional groupspresent on the FCC substrate.

Considering the peak current densities, per FIG. 13A, and the exemplarycapacitance values in FIG. 13B, the capacitance exhibited by theexemplary PANI-FCC device is about 667 F/g at a 1 A/g current density,whereas the capacitance of the exemplary PANI-CC device is about 341 F/gunder the same condition. As acid treatment of the CC imposes negativelycharged carboxylic group functionalities on the CC's surfaces, theimmersion of the FCC into the polymerization fluid may create anelectrostatic interaction between the carboxylic acid groups and thepositively charged anilinium ions, which may lead to a strongerconjugation product. As such, the improvement in supercapacitiveperformance of the exemplary PANI-FCC device may be due to the combinedeffects of the better interaction between PANI and the functional groupspresent on the FCC substrate (i.e. the faster electron exchange betweenPANI and FCC), as well as the redox activity of the functional groupsthemselves.

Nyquist and Bode plots are shown in FIGS. 13C and 13D, respectively, forexemplary CC, FCC, PANI-CC, and PANI-FCC devices operated under an opencircuit potential. Per FIG. 13C, the exemplary PANI-FCC device displaysa lower equivalent series resistance, as evaluated from the x-intercept,than the exemplary PANI-CC, which confirms the low IR drop measurementsshown in FIG. 13B. The Bode plot, per FIG. 13D, of the exemplary PANI-CCdevice also displays a larger phase angle, confirming the lower deviceresistance, as observed in the Nyquist plot in FIG. 13C.

Additionally, the scan rate measurements displayed in FIG. 13E from 10mV/s to 1,000 mV/s, show that the exemplary PANI-FCC device retained asimilar CV curve shape at a high scan rate of 200 mV/s, indicating agood rate capability, that is confirmed by the CD plots in FIG. 13F. Thelarge pore volumes which may be filled with a redox active electrolyteallow for charge storage through both adsorption and redox capacitance.As expected, the electrolyte species readily inserted and de-insertedinto and out of the electrode surfaces and throughout the pores of theexemplary PANI-FCC device at low scan rates, resulting in the expectedrectangular response curve. As the scan rate increases, the interactionbetween the electrolyte species and the electrode surfaces istheoretically limited by kinetic and mass transport parameters.

In such a case, a large proportion of the substrate surfaces have littledynamic interaction with the electrolyte, possibly resulting in thenon-rectangular and tilted CV curve. The similar CD example plots atdifferent current densities (1-50 A/g), as shown in FIG. 13F serve as anadditional indication of the exemplary device's good rate capability.

The exemplary PANI-FCC device also maintained its electrochemicalperformance, even when operated at high CD rates. FIG. 13G shows thespecific capacitances as a function of the current density of theexemplary PANI-FCC device, compared with the exemplary PANI-CC device.The rate capability of the exemplary symmetric device tested atdifferent current densities from 1 to 50 A/g shows an excellent specificcapacitance of 274 F/g at a current density of 50 A/g. The specificcapacitance of the exemplary PANI-FCC device (upper curve) at 20 A/g and50 A/g is as much as about 56% and about 41% of that at 1 A/g,respectively. These results demonstrate the good rate capability of theexemplary PANI-FCC device under high current densities, which isimportant for practical high rate SC applications.

The capacitance retention over the long-term charge/discharge cycles isindispensable for practical SC materials. The capacitance of theexemplary PANI-FCC device is measured during CD cycling at a range ofcurrent densities (1, 2, 5, 10, and 20 A/g) over 5,000 cycles, per FIG.13H, whereas the capacitance of the exemplary device in a currentdensity of 1 A/g increases during the first 200 cycles, and whereas thecapacitance of the exemplary device decreases during the period from1,000 to 5,000 cycles. After 200 cycles at a current density of 1 A/g,the specific capacitance of the exemplary device decreases, and at theend of the 1,000th cycle, the exemplary device provides about 91% of itsinitial specific capacitance of 667 F/g. Finally, the exemplary deviceexhibits a capacitance retention of about 87% over 5,000 cycles,indicating very good cyclability. The inset in FIG. 13H additionallydisplays the 1st and 5,000th cycles of the exemplary PANI-FCC electrodeat 1 A/g.

Per FIG. 14, examples of CD curves are shown for an exemplary PANI-FCCdevice in different currents to calculate its areal capacitance. Theareal capacitance of exemplary stack is about 374 mF/cm² in 7 mA/cm²(equivalent to 1 A/g current).

After functionalization, an exemplary FCC is annealed in a furnace in anair atmosphere at 200° C. for 1 hour, 4 hours, or 7 hours., theexemplary PANI-(unannealed)FCC device displays a much higher dischargetime than the exemplary PANI-(annealed)FCC device. As shown in FIG. 15A,increasing the annealing time increases the discharge time of theexemplary PANI-FCC device, without effecting its capacitance, mostlikely due to the fact that annealing reduces the number, and thus thepseudocapacitance, of the functional groups present on the CC.Additionally, FIG. 15B depicts that increasing the annealing timedecreases the semicircle in the high frequency region, indicating areduction the charge transfer resistance, most likely due to the factthat as the functional groups on the FCC decrease during annealing, theFCC conductivity increases. As such, annealing the exemplary FCC devicereduces the functional pseudocapacitance, increases conductivity, anddecreases the exemplary device's resistance. The period of annealingdoes not seem to affect the capacitance of the exemplary devices.

The performance of an exemplary device under a constant mechanicalstress displays its ability to act as a flexible energy storage device.FIG. 16A shows the resistance of the exemplary PANI-FCC device decreasesunder mechanical stress from a flat condition at 0° to a bent conditionat 180°. Additionally, FIG. 16B displays that the device's resistance,per this example, is maintained within about 4%, as it is bent from itsflat to its folded condition over 1,000 cycles. The as-preparedexemplary device exhibits a high flexibility and may be bent 180°without a loss in performance. Additionally, per FIG. 16C, the exemplaryPANI-FCC device maintains its rectangularly shaped CV curve andcapacitance in its folded condition. This excellent performancedurability of the exemplary device may be attributed to the highmechanical flexibility of the electrodes and the strong connectionsbetween FCC and PANI, and proves that such a device is suitable forflexible use.

FIGS. 17A-D display the electrochemical performance of an exemplaryasymmetric device comprising a PANI-FCC positive electrode, an activatedcarbon negative electrode, and a 1 M H₂SO₄ electrolyte. Per the examplemeasurement shown in FIG. 17A, the AC electrode has a predefined voltagepotential window of 1.2 V (−0.6 to 0.6 V) which is limited by the waterredox range of H₂ evolution. FIGS. 17B and 17C show the CV and CD of theabove exemplary device at 50 mV/s and 1 A/g, respectively, whereas thepotential window for the asymmetric device is extended to the aqueouselectrolyte oxidation wall of 1.3 V, beyond the capabilities of the ACelectrode.

Power density and energy density are the two main parameters used toevaluate a supercapacitor device's performance. FIG. 17D depicts aRagone plot which compares the energy densities and the power densitiesof the exemplary PANI-FCC symmetric and asymmetric devices over a rangeof current densities from 1 A/g to 50 A/g. Per FIG. 17D, the maximumenergy density of the exemplary symmetric device is about 59 Wh/Kg,which decreased to about 24 Wh/kg as the power density increased fromabout 0.4 kW/kg to about 20 kW/kg. The energy and power density of theexemplary asymmetric device increased to about 91 Wh/kg and 33 W/kg,respectively.

FIGS. 23A and 23B display exemplary device applications, whereas twoasymmetric PANI-FCC//AC devices connected in series, successfullypowered a 5 mm diameter red LED 2101 indicator for about 47 minutes, anda clock 2102 for 1 h and 17 min, respectively.

NQ is an effective redox-active electrolyte which is capable ofproviding additional redox reactions. In one embodiment, theelectrochemical performance of an exemplary PANI/AC asymmetricsupercapacitor device with a 1 M H₂SO₄+10 millimolar NQ mixed gelelectrolyte is shown in FIGS. 18A-F, whereas the addition of NQ extendsthe measured potential window. The CV curves of the exemplary asymmetricPANI/AC device with an NQ electrolyte at different voltage windows andat 100 mV/s are shown in FIG. 18A, whereas the potential windows areseen to extended to 1.7 V. The relationship between the potential windowand the capacitance of the exemplary device is seen in the inset of FIG.18A, whereas a 1.4 V potential window allows for the highestcapacitance. FIG. 18B shows that the implementation of the H₂SO₄+NQmixed electrolyte in the exemplary device increases the integrated areaof cyclic voltammetry compared with H₂SO₄ electrolyte. The Nyquist plotsof the PANI/AC devices in the mixed and uniform electrolytes, per FIG.18C, also proves that the exemplary PANI/AC device in the mixedelectrolyte exhibits a lower equivalent series resistance of 2.5Ω thanin the uniform electrolyte (3.1Ω) due to the high electricalconductivity of the electrolyte. As the exemplary PANI/AC device in themixed electrolyte additionally exhibits a smaller semicircle in the highfrequency region, per the inset graph than the PANI/AC device in theH₂SO₄ electrolyte, the mixed electrode device exhibits a highercapacitance. Additionally, as the equivalent series resistance of theexemplary PANI/AC device in the H₂SO₄+NQ electrolyte, per themeasurements in FIG. 18C, is lower than the calculated equivalent seriesresistance of the exemplary PANI/AC device without NQ, the lower chargetransfer resistance of the NQ may improve the capacitance of the devicethrough increased electron transfer. The appearance of a plateau in thedischarge curve of the exemplary mixed electrolyte device, at differentcurrent densities per FIG. 18D, confirms the contribution of NQ towardsincreasing the discharge time to about 2,000 seconds in a currentdensity of 2 A/g. As calculated per the values in FIG. 18D, the additionof 10 millimolar 1,4-naphthoquinon (NQ) into the 1 M H₂SO₄ produces amixed electrolyte and an exemplary device which exhibits a specificcapacity of about 3,200 F/g, in a current density of 1 A/g, and anenergy density of about 827 Wh/kg, performing more than 8 times betterthan the exemplary device in the absence of NQ.

The inset of FIG. 18D, and FIG. 18E display the CD curve of theexemplary mixed electrode device at a current density of 50 A/g, and thecalculated capacitance as a function of current density, respectively,which highlight the high rate capability, and capacity of about 671 F/g.Finally, FIG. 18F shows the Ragone plots of an exemplary device, withand without the presence of NQ in the electrolyte, to highlight the 8fold positive effect of NQ on energy density.

The addition of NQ is capable of not only increasing the capacitance ofthe PANI redox active electrodes, but also improves the capacitance ofEDLC materials such as activated carbons. FIG. 19A shows the cyclicvoltammogram of an exemplary device comprising an activated carbonelectrode in PVA/H₂SO₄ gel redox electrolyte, which demonstrates anoutstanding capacitance of about 13,456 F/g. As activated carbon, withits high hydrogen evolution overpotential, may operate at more negativevoltages without causing electrolyte decomposition, an exemplaryasymmetric supercapacitor exhibits an extended voltage window and acontrolled charge storage capacity, via a redox electrolyte that acts onthe negative and positive electrodes simultaneously. FIG. 19B shows CDcurves of exemplary asymmetric AC-FCC and PANI-FCC electrodes in a 3Ecell (triple stacked) configuration at a current density of 10 A/g, theresults of which agree with that of CV experiments. FIG. 19C depictsthat the exemplary device exhibits a long discharge time of about 2,000seconds under a current density of 2 A/g. The appearance of a newplateau in the discharge curve may confirm the contribution from NQtowards the capacitance of the exemplary device. The inset to FIG. 19Cdemonstrates the CD curve of the device at a very high current density(100 A/g), revealing the high rate capability of the AC-FCC//PANI-FCCdevice in the presence of NQ.

CAPACITANCE ENERGY DENSITY VOLTAGE DEVICE ELECTROLYTE (F/g) (Wh/kg) (V)CC//CC H₂SO₄ 8 0.7 0.8 FCC//FCC H₂SO₄ 126 11.2 0.8 PANI//PANI H₂SO₄ 48042.6 0.8 0.5 mM NQ-in-H₂SO₄ (liquid) 691 61.4 0.8 10 mM NQ-in-H₂SO₄(gel) 710 63.1 0.8 PANI//AC H₂SO₄ 276 64.8 1.3 0.5 mM NQ-in-H₂SO₄(liquid) 383 76.6 1.2 H₂SO₄ (gel) 314 62.8 1.2 10 mM NQ-in-H₂SO₄ (gel)5,661 @ 2 A/g 1,541 1.4 PANI//PANI//PANI 10 mM NQ-in-H₂SO₄ (gel) 10,706@ 10 A/g — −1 AC//AC//AC 10 mM NQ-in-H₂SO₄ (gel) 13,456 @ 10 A/g — −1.1

FIG. 20A shows the performance of an exemplary asymmetric supercapacitorcomprising a PANI-FCC positive electrode and an AC-FCC negativeelectrode in an acidic polymer hydrogel electrolyte with and without theredox additive. This asymmetric supercapacitor bypasses the inherentlylow voltage of symmetric polyaniline devices (0.8 V) and extends theoperation voltage window to 1.4 V. Furthermore, the integrated area ofthe cyclic voltammogram is obviously much higher in the presence of theredox additive. The charge and discharge curves in FIG. 20B show adischarge time of about 6,000 seconds under a current density of 1.88A/g, whereas in the absence of NQ the same device discharges in only 185seconds. In other words, the specific capacitance of the device in thepresence of NQ is about 5,661 F/g (2.3 F/cm²) under a current density of1.88 A/g, which is more than 20 times higher than that in the absence ofNQ.

FIG. 20C shows that the device maintains a high specific capacitanceeven at very high current densities of up to 94 A/g, revealing the highrate capability of the exemplary AC-FCC//PANI-FCC device in the presenceof NQ.

Additionally, the charge/discharge (GCD) cycling of the AC-FCC//PANI-FCCdevice under a current density of 47 A/g, per FIG. 20D, indicates an 84%capacitance retention over 7,000 cycles.

FIG. 21 displays an exemplary relationship between the power density andthe energy density of exemplary symmetric and asymmetric devices, inaccordance with some embodiments.

An exemplary redox supercapacitor constructed in accordance with thepresent disclosure demonstrates an outstanding energy density of 1,541Wh/kg based on the mass of the active materials only.

Examples

In one example, an exemplary electrochemical cell has a footprint ofabout 1 cm² and a thickness of about 1 millimeter, thus encompassing avolume of 0.005 cm³. In this example, the composition of the exemplaryelectrochemical cell is shown below.

Mass (g) Density (g/cm³) Volume (cm³) CC 0.005 1.55 0.0032 PANI 0.00011.33 7.54 × 10⁻⁵ AC 0.0001 0.5 0.0002 NQ 0.000085 1.42 5.99 × 10⁻⁵

In this example of the electrochemical cell, as the SEM images, per FIG.5A, display that the PANI nanotubes have a porosity of about 28.4%, theactual PANI volume is calculated to be about 1.05×10⁻⁴ cm³.Additionally,

In this example, the exemplary electrochemical cell displays acapacitance, voltage, and energy of about 1.14 F, 1.4 V, and 0.0003 Wh,respectively. Additionally, FIG. 22, displays the gravimetric andvolumetric densities of an asymmetric PANI//AC device with an NQ redoxelectrolyte and carbon cloth, as normalized by the mass and volume ofthe electrodes (1554 Wh/kg, 1019 Wh/L), by the mass and volume of theelectrodes and the redox electrolyte (1091 Wh/kg, 851 Wh/L), and by themass and volume of the electrodes, the redox electrolyte and the carboncloth (59 Wh/kg. 87 Wh/L).

Terms and Definitions

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich the device described herein belongs. As used in this specificationand the appended claims, the singular forms “a,” “an,” and “the” includeplural references unless the context clearly dictates otherwise. Anyreference to “or” herein is intended to encompass “and/or” unlessotherwise stated.

As used herein, and unless otherwise specified, the term AC refers toactivated carbon.

As used herein, and unless otherwise specified, the term CC refers tocarbon cloth.

As used herein, and unless otherwise specified, the term FCC refers tofunctionalized carbon cloth.

As used herein, and unless otherwise specified, the term PANI refers toPolyaniline.

As used herein, and unless otherwise specified, the term PANI-CC refersto a carbon cloth, on which Polyaniline structures have beensynthesized.

As used herein, and unless otherwise specified, the term PANI-FCC refersto a functionalized carbon cloth, on which polyaniline structures havebeen synthesized.

As used herein, and unless otherwise specified, the term SDS refers tosodium dodecyl sulfate.

As used herein, and unless otherwise specified, a CV chart refers to acyclic voltammogram chart.

As used herein, and unless otherwise specified, a CD chart refers to acharge-discharge chart.

While preferable embodiments of the present methods and devices taughtherein have been shown and described herein, it will be obvious to thoseskilled in the art that such embodiments are provided by way of exampleonly. Numerous variations, changes, and substitutions will now occur tothose skilled in the art without departing from the methods and devicestaught herein. It should be understood that various alternatives to theembodiments of the methods and devices taught herein described hereinmay be employed in practicing the methods and devices taught herein. Itis intended that the following claims define the scope of the methodsand devices taught herein and that methods and structures within thescope of these claims and their equivalents be covered thereby.

As used herein, and unless otherwise specified, the term “about” or“approximately” means an acceptable error for a particular value asdetermined by one of ordinary skill in the art, which depends in part onhow the value is measured or determined. In certain embodiments, theterm “about” or “approximately” means within 1, 2, 3, or 4 standarddeviations. In certain embodiments, the term “about” or “approximately”means within 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%,1%, 0.5%, 0.1%, or 0.05% of a given value or range.

In certain embodiments, the term “about” or “approximately” means within100 nanometers, 90 nanometers, 80 nanometers, 70 nanometers, 60nanometers, 50 nanometers, 40 nanometers, 30 nanometers, 20 nanometers,10 nanometers, 9 nanometers, nanometers, 8 nanometers, 7 nanometers, 6nanometers, 5 nanometers, 4 nanometers, 3 nanometers, 2 nanometers, or 1nanometers of a given value or range. In certain embodiments, the term“about” or “approximately” means within 100 mF/cm², 90 mF/cm², 80mF/cm², 70 mF/cm², 60 mF/cm², 50 mF/cm², 40 mF/cm², 30 mF/cm², 20mF/cm², 10 mF/cm², 9 mF/cm², mF/cm², 8 mF/cm², 7 mF/cm², 6 mF/cm², 5mF/cm², 4 mF/cm², 3 mF/cm², 2 mF/cm², or 1 mF/cm² of a given value orrange. In certain embodiments, the term “about” or “approximately” meanswithin 5V, 4V, 3V, 2V, 1V, 0.5V, 0.1V, or 0.05V of a given value orrange. In certain embodiments, the term “about” or “approximately” meanswithin 100 F/g, 90 F/g, 80 F/g, 70 F/g, 60 F/g, 50 F/g, 40 F/g, 30 F/g,20 F/g, 10 F/g, 9 F/g, F/g, 8 F/g, 7 F/g, 6 F/g, 5 F/g, 4 F/g, 3 F/g, 2F/g, or 1 F/g of a given value or range. In certain embodiments, theterm “about” or “approximately” means within 100 Wh/kg, 80 Wh/kg, 60Wh/kg, 40 Wh/kg, 20 Wh/kg, 15 Wh/kg, 10 Wh/kg, 9 Wh/kg, 8 Wh/kg, 7Wh/kg, 6 Wh/kg, 5 Wh/kg, 4 Wh/kg, 3 Wh/kg, 2 Wh/kg, 1 Wh/kg, 0.5 Wh/kg,0.1 Wh/kg, or 0.05 Wh/kg of a given value or range. In certainembodiments, the term “about” or “approximately” means within 40° C.,30° C., 20° C., 10° C., 9° C., ° C., 8° C., 7° C., 6° C., 5° C., 4° C.,3° C., 2° C., or 1° C. of a given value or range. In certainembodiments, the term “about” or “approximately” means within 60minutes, 50 minutes, 40 minutes, 30 minutes, 20 minutes, 10 minutes, 9minutes, minutes, 8 minutes, 7 minutes, 6 minutes, 5 minutes, 4 minutes,3 minutes, 2 minutes, or 1 minute of a given value or range. In certainembodiments, the term “about” or “approximately” means within 60 hours,50 hours, 40 hours, 30 hours, 20 hours, 10 hours, 9 hours, hours, 8hours, 7 hours, 6 hours, 5 hours, 4 hours, 3 hours, 2 hours, or 1 hourof a given value or range. In certain embodiments, the term “about” or“approximately” means within 40.0 grams, 30.0 grams, 20.0 grams, 10.0grams, 5.0 grams, 1.0 grams, 0.9 grams, 0.8 grams, 0.7 grams, 0.6 grams,0.5 grams, 0.4 grams, 0.3 grams, 0.2 grams or 0.1 grams, 0.05 grams, or0.01 grams of a given value or range. In certain embodiments, the term“about” or “approximately” means within 30.0 A/g, 20.0 A/g, 10.0A/g, 5.0A/g, 1.0 A/g, 0.9 A/g, 0.8 A/g, 0.7 A/g, 0.6 A/g, 0.5 A/g, 0.4 A/g, 0.3A/g, 0.2 A/g, or 0.1 A/g of a given value or range. In certainembodiments, the term “about” or “approximately” means within 20 kW/kg,15 kW/kg, 10 kW/kg, 9 kW/kg, 8 kW/kg, 7 kW/kg, 6 kW/kg, 5 kW/kg, 4kW/kg, 3 kW/kg, 2 kW/kg, 1 kW/kg, 0.5 kW/kg, 0.1 kW/kg, or 0.05 kW/kg ofa given value or range. In certain embodiments, the term “about” or“approximately” means within 5 L, 4 L, 3 L, 2 L, 1 L, 0.5 L, 0.1 L, or0.05 L. In certain embodiments, the term “about” or “approximately”means within 30.0 ml, 20.0 ml, 10.0 ml, 5.0 ml, 1.0 ml, 0.9 ml, 0.8 ml,0.7 ml, 0.6 ml, 0.5 ml, 0.4 ml, 0.3 ml, 0.2 ml, or 0.1 ml of a givenvalue or range. In certain embodiments, the term “about” or“approximately” means within 5 M, 4 M, 3 M, 2 M, 1 M, 0.5 M, 0.1 M, or0.05 M of a given value or range.

What is claimed is:
 1. An energy storage device comprising: two or moreelectrodes, wherein at least one of the two or more electrodes comprisesa functionalized carbon electrode comprising a carbon substrate and oneor more conducting polymer polygonal nanotubes disposed on the carbonsubstrate; a current collector; and a redox electrolyte in directcontact with an interior surface and an exterior surface of the one ormore conducting polymer polygonal nanotubes.
 2. The energy storagedevice of claim 1, wherein the one or more conducting polymer polygonalnanotubes have a length of 100 nanometers to 10,000 nanometers.
 3. Theenergy storage device of claim 1, wherein the one or more conductingpolymer polygonal nanotubes have an outer width of 10 nanometers to1,000 nanometers.
 4. The energy storage device of claim 1, wherein theone or more conducting polymer polygonal nanotubes have an inner widthof 50 nanometers to 800 nanometers.
 5. The energy storage device ofclaim 1, wherein a surface of the one or more conducting polymerpolygonal nanotubes contains a nanostructure.
 6. The energy storagedevice of claim 1, wherein the redox electrolyte comprises a quinone. 7.A method of fabricating a functionalized carbon electrode comprising:(a) functionalizing a carbon substrate to form a functionalized carbonsubstrate; (b) preparing the functionalized carbon substrate; (c)formulating a polymerization fluid; and (d) synthesizing one or moreconducting polymer polygonal nanotubes on the functionalized carbonsubstrate.
 8. The method of claim 7, wherein the functionalizing of thecarbon substrate to form the functionalized carbon substrate comprises:(i) forming a functionalization solution; (ii) heating thefunctionalization solution; (iii) cooling the functionalizationsolution; (iv) displacing a piece of the carbon substrate into thefunctionalization solution to form a piece of the functionalized carbonsubstrate; and (v) rinsing the piece of the functionalized carbonsubstrate.
 9. The method of claim 8, wherein the heating of thefunctionalization solution occurs at a temperature of 30° C. to 120° C.10. The method of claim 8, wherein the heating of the functionalizationsolution occurs for a period of time of 60 minutes to 240 minutes. 11.The method of claim 7, further comprising a step of annealing thefunctionalized carbon substrate after the carbon substrate isfunctionalized.
 12. The method of claim 11, wherein the functionalizedcarbon substrate is annealed at a temperature of 100° C. to 400° C. 13.The method of claim 7, wherein the preparing of the functionalizedcarbon substrate comprises: (i) cutting a piece of the functionalizedcarbon substrate; (ii) submerging the piece of functionalized carbonsubstrate in a solvent solution; (iii) sonicating the piece offunctionalized carbon substrate in the solvent solution; and (iv) dryingthe piece of functionalized carbon substrate.
 14. The method of claim13, wherein the sonicating occurs for a period of time of 15 minutes to60 minutes.
 15. The method of claim 13, wherein the drying occurs over aperiod of time of 3 hours to 12 hours.
 16. The method of claim 7,wherein the formulating of the polymerization fluid comprises: (i)forming a polymerization solution comprising: a conducting polymer; anacid; a detergent; water; and an oxidizing agent; and (ii) stirring thepolymerization solution to form the polymerization fluid.
 17. The methodof claim 16, wherein the stirring of the polymerization solution occursfor a period of time of 10 minutes to 40 minutes.
 18. The method ofclaim 7, wherein the synthesizing of the one or more conducting polymerpolygonal nanotubes on the functionalized carbon substrate comprises:(i) agitating the polymerization fluid; (ii) immersing thefunctionalized carbon substrate in the polymerization fluid; (iii)storing the functionalized carbon substrate in the polymerization fluid;(iv) removing the functionalized carbon substrate from thepolymerization fluid; (v) washing the functionalized carbon substrate;and (vi) drying the functionalized carbon substrate.
 19. The method ofclaim 18, wherein the storing of the functionalized carbon substrate inthe polymerization fluid occurs at a temperature of 10° C. to 50° C. 20.The method of claim 18, wherein the storing of the functionalized carbonsubstrate in the polymerization fluid occurs for a period of time of atleast 8 hours.